diff --git a/.github/workflows/README.md b/.github/workflows/README.md
index 7089501d5e405..78303c2c64b86 100644
--- a/.github/workflows/README.md
+++ b/.github/workflows/README.md
@@ -18,3 +18,25 @@ Some architectural notes about key decisions and concepts in our workflows:
 - **head commit**: The HEAD commit in the pull request's branch. Same as `github.event.pull_request.head.sha`.
 - **merge commit**: The temporary "test merge commit" that GitHub Actions creates and updates for the pull request. Same as `refs/pull/${{ github.event.pull_request.number }}/merge`.
 - **target commit**: The base branch's parent of the "test merge commit" to compare against.
+
+## Concurrency Groups
+
+We use [GitHub's Concurrency Groups](https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/control-the-concurrency-of-workflows-and-jobs) to cancel older jobs on pushes to Pull Requests.
+When two workflows are in the same group, a newer workflow cancels an older workflow.
+Thus, it is important how to construct the group keys:
+
+- Because we want to run jobs for different events at same time, we add `github.event_name` to the key. This is the case for the `pull_request` which runs on changes to the workflow files to test the new files and the same workflow from the base branch run via `pull_request_event`.
+
+- We don't want workflows of different Pull Requests to cancel each other, so we include `github.event.pull_request.number`. The [GitHub docs](https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/control-the-concurrency-of-workflows-and-jobs#example-using-a-fallback-value) show using `github.head_ref` for this purpose, but this doesn't work well with forks: Different users could have the same head branch name in their forks and run CI for their PRs at the same time.
+
+- Sometimes, there is no `pull_request.number`. That's the case for `push` or `workflow_run` events. To ensure non-PR runs are never cancelled, we add a fallback of `github.run_id`. This is a unique value for each workflow run.
+
+- Of course, we run multiple workflows at the same time, so we add `github.workflow` to the key. Otherwise workflows would cancel each other.
+
+- There is a special case for reusable workflows called via `workflow_call` - they will have `github.workflow` set to their parent workflow's name. Thus, they would cancel each other. That's why we additionally hardcode the name of the workflow as well.
+
+This results in a key with the following semantics:
+
+```
+<running-workflow>-<triggering-workflow>-<triggered-event>-<pull-request/fallback>
+```
diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
index 9cd96cd4e73fc..72b8482ef439d 100644
--- a/.github/workflows/backport.yml
+++ b/.github/workflows/backport.yml
@@ -10,7 +10,7 @@ on:
     types: [closed, labeled]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: backport-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions:
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index d92f73eb0d3aa..a46a382ff42db 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -7,7 +7,7 @@ on:
   pull_request_target:
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: build-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index b348bef5bfc0d..dfe5999df23ff 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -7,7 +7,7 @@ on:
   pull_request_target:
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: check-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}
diff --git a/.github/workflows/codeowners-v2.yml b/.github/workflows/codeowners-v2.yml
index 84bbbc9806332..947f441f2e60e 100644
--- a/.github/workflows/codeowners-v2.yml
+++ b/.github/workflows/codeowners-v2.yml
@@ -30,7 +30,7 @@ on:
     types: [opened, ready_for_review, synchronize, reopened]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: codeowners-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}
diff --git a/.github/workflows/dismissed-review.yml b/.github/workflows/dismissed-review.yml
new file mode 100644
index 0000000000000..e8ab48bda0755
--- /dev/null
+++ b/.github/workflows/dismissed-review.yml
@@ -0,0 +1,65 @@
+name: Dismissed review
+
+on:
+  workflow_run:
+    workflows:
+      - Review dismissed
+    types: [completed]
+
+concurrency:
+  group: dismissed-review-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  pull-requests: write
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  # The `check-cherry-picks` workflow creates review comments which reviewers
+  # are encouraged to manually dismiss if they're not relevant.
+  # When a CI-generated review is dismissed, this job automatically minimizes
+  # it, preventing it from cluttering the PR.
+  minimize:
+    name: Minimize as resolved
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          script: |
+            // PRs from forks don't have any PRs associated by default.
+            // Thus, we request the PR number with an API call *to* the fork's repo.
+            // Multiple pull requests can be open from the same head commit, either via
+            // different base branches or head branches.
+            const { head_repository, head_sha, repository } = context.payload.workflow_run
+            await Promise.all(
+              (await github.paginate(github.rest.repos.listPullRequestsAssociatedWithCommit, {
+                owner: head_repository.owner.login,
+                repo: head_repository.name,
+                commit_sha: head_sha
+              }))
+              .filter(pull_request => pull_request.base.repo.id == repository.id)
+              .map(async (pull_request) =>
+                Promise.all(
+                  (await github.paginate(github.rest.pulls.listReviews, {
+                    owner: context.repo.owner,
+                    repo: context.repo.repo,
+                    pull_number: pull_request.number
+                  })).filter(review =>
+                    review.user.login == 'github-actions[bot]' &&
+                    review.state == 'DISMISSED'
+                  ).map(review => github.graphql(`
+                    mutation($node_id:ID!) {
+                      minimizeComment(input: {
+                        classifier: RESOLVED,
+                        subjectId: $node_id
+                      })
+                      { clientMutationId }
+                    }`,
+                    { node_id: review.node_id }
+                  ))
+                )
+              )
+            )
diff --git a/.github/workflows/edited.yml b/.github/workflows/edited.yml
index 186bd9cb8a0c6..49fccb5f48ba0 100644
--- a/.github/workflows/edited.yml
+++ b/.github/workflows/edited.yml
@@ -17,7 +17,7 @@ on:
     types: [edited]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: edited-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}
diff --git a/.github/workflows/eval-aliases.yml b/.github/workflows/eval-aliases.yml
index 913341d6c8148..599d82a93e51d 100644
--- a/.github/workflows/eval-aliases.yml
+++ b/.github/workflows/eval-aliases.yml
@@ -7,7 +7,7 @@ on:
   pull_request_target:
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: eval-aliases-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}
diff --git a/.github/workflows/eval.yml b/.github/workflows/eval.yml
index 711932b6a02bc..dd7c433815dc9 100644
--- a/.github/workflows/eval.yml
+++ b/.github/workflows/eval.yml
@@ -17,7 +17,7 @@ on:
       - python-updates
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: eval-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}
@@ -217,46 +217,6 @@ jobs:
           name: comparison
           path: comparison/*
 
-      - name: Labelling pull request
-        if: ${{ github.event_name == 'pull_request_target' }}
-        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
-        with:
-          script: |
-            const { readFile } = require('node:fs/promises')
-
-            const pr = {
-              owner: context.repo.owner,
-              repo: context.repo.repo,
-              issue_number: context.payload.pull_request.number
-            }
-
-            // Get all currently set labels that we manage
-            const before =
-              (await github.paginate(github.rest.issues.listLabelsOnIssue, pr))
-              .map(({ name }) => name)
-              .filter(name => name.startsWith('10.rebuild') || name == '11.by: package-maintainer')
-
-            // And the labels that should be there
-            const after = JSON.parse(await readFile('comparison/changed-paths.json', 'utf-8')).labels
-
-            // Remove the ones not needed anymore
-            await Promise.all(
-              before.filter(name => !after.includes(name))
-              .map(name => github.rest.issues.removeLabel({
-                ...pr,
-                name
-              }))
-            )
-
-            // And add the ones that aren't set already
-            const added = after.filter(name => !before.includes(name))
-            if (added.length > 0) {
-              await github.rest.issues.addLabels({
-                ...pr,
-                labels: added
-              })
-            }
-
       - name: Add eval summary to commit statuses
         if: ${{ github.event_name == 'pull_request_target' }}
         uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
@@ -289,6 +249,14 @@ jobs:
               target_url
             })
 
+  labels:
+    name: Labels
+    needs: [ compare ]
+    uses: ./.github/workflows/labels.yml
+    permissions:
+      issues: write
+      pull-requests: write
+
   reviewers:
     name: Reviewers
     # No dependency on "compare", so that it can start at the same time.
@@ -298,5 +266,3 @@ jobs:
     if: needs.prepare.outputs.targetSha
     uses: ./.github/workflows/reviewers.yml
     secrets: inherit
-    with:
-      caller: ${{ github.workflow }}
diff --git a/.github/workflows/labels.yml b/.github/workflows/labels.yml
index 1e485a6df89be..a7e34775d6eaa 100644
--- a/.github/workflows/labels.yml
+++ b/.github/workflows/labels.yml
@@ -6,14 +6,18 @@
 name: "Label PR"
 
 on:
-  pull_request_target:
+  workflow_call:
+  workflow_run:
+    workflows:
+      - Review dismissed
+      - Review submitted
+    types: [completed]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: labels-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions:
-  contents: read
   issues: write # needed to create *new* labels
   pull-requests: write
 
@@ -27,8 +31,114 @@ jobs:
     runs-on: ubuntu-24.04-arm
     if: "!contains(github.event.pull_request.title, '[skip treewide]')"
     steps:
+      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        id: eval
+        with:
+          script: |
+            const run_id = (await github.rest.actions.listWorkflowRuns({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              workflow_id: 'eval.yml',
+              event: 'pull_request_target',
+              head_sha: context.payload.pull_request?.head.sha ?? context.payload.workflow_run.head_sha
+            })).data.workflow_runs[0]?.id
+            core.setOutput('run-id', run_id)
+
+      - name: Download the comparison results
+        if: steps.eval.outputs.run-id
+        uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
+        with:
+          run-id: ${{ steps.eval.outputs.run-id }}
+          github-token: ${{ github.token }}
+          pattern: comparison
+          path: comparison
+          merge-multiple: true
+
+      - name: Labels from eval
+        if: steps.eval.outputs.run-id && github.event_name != 'pull_request'
+        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        with:
+          script: |
+            const { readFile } = require('node:fs/promises')
+
+            let pull_requests
+            if (context.payload.workflow_run) {
+              // PRs from forks don't have any PRs associated by default.
+              // Thus, we request the PR number with an API call *to* the fork's repo.
+              // Multiple pull requests can be open from the same head commit, either via
+              // different base branches or head branches.
+              const { head_repository, head_sha, repository } = context.payload.workflow_run
+              pull_requests = (await github.paginate(github.rest.repos.listPullRequestsAssociatedWithCommit, {
+                owner: head_repository.owner.login,
+                repo: head_repository.name,
+                commit_sha: head_sha
+              })).filter(pull_request => pull_request.base.repo.id == repository.id)
+            } else {
+              pull_requests = [ context.payload.pull_request ]
+            }
+
+            await Promise.all(
+              pull_requests.map(async (pull_request) => {
+                const pr = {
+                  owner: context.repo.owner,
+                  repo: context.repo.repo,
+                  issue_number: pull_request.number
+                }
+
+                // Get all currently set labels that we manage
+                const before =
+                  (await github.paginate(github.rest.issues.listLabelsOnIssue, pr))
+                  .map(({ name }) => name)
+                  .filter(name =>
+                    name.startsWith('10.rebuild') ||
+                    name == '11.by: package-maintainer' ||
+                    name.startsWith('12.approvals:') ||
+                    name == '12.approved-by: package-maintainer'
+                  )
+
+                const approvals = new Set(
+                  (await github.paginate(github.rest.pulls.listReviews, {
+                    owner: context.repo.owner,
+                    repo: context.repo.repo,
+                    pull_number: pull_request.number
+                  }))
+                  .filter(review => review.state == 'APPROVED')
+                  .map(review => review.user.id)
+                )
+
+                const maintainers = new Set(Object.keys(
+                  JSON.parse(await readFile('comparison/maintainers.json', 'utf-8'))
+                ))
+
+                // And the labels that should be there
+                const after = JSON.parse(await readFile('comparison/changed-paths.json', 'utf-8')).labels
+                if (approvals.size > 0) after.push(`12.approvals: ${approvals.size > 2 ? '3+' : approvals.size}`)
+                if (Array.from(maintainers).some(m => approvals.has(m))) after.push('12.approved-by: package-maintainer')
+
+                // Remove the ones not needed anymore
+                await Promise.all(
+                  before.filter(name => !after.includes(name))
+                  .map(name => github.rest.issues.removeLabel({
+                    ...pr,
+                    name
+                  }))
+                )
+
+                // And add the ones that aren't set already
+                const added = after.filter(name => !before.includes(name))
+                if (added.length > 0) {
+                  await github.rest.issues.addLabels({
+                    ...pr,
+                    labels: added
+                  })
+                }
+              })
+            )
+
       - uses: actions/labeler@8558fd74291d67161a8a78ce36a881fa63b766a9 # v5.0.0
+        name: Labels from touched files
         if: |
+          github.event_name != 'workflow_run' &&
           github.event.pull_request.head.repo.owner.login != 'NixOS' || !(
             github.head_ref == 'haskell-updates' ||
             github.head_ref == 'python-updates' ||
@@ -39,8 +149,11 @@ jobs:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           configuration-path: .github/labeler.yml # default
           sync-labels: true
+
       - uses: actions/labeler@8558fd74291d67161a8a78ce36a881fa63b766a9 # v5.0.0
+        name: Labels from touched files (no sync)
         if: |
+          github.event_name != 'workflow_run' &&
           github.event.pull_request.head.repo.owner.login != 'NixOS' || !(
             github.head_ref == 'haskell-updates' ||
             github.head_ref == 'python-updates' ||
@@ -51,11 +164,14 @@ jobs:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           configuration-path: .github/labeler-no-sync.yml
           sync-labels: false
+
       - uses: actions/labeler@8558fd74291d67161a8a78ce36a881fa63b766a9 # v5.0.0
+        name: Labels from touched files (development branches)
         # Development branches like staging-next, haskell-updates and python-updates get special labels.
         # This is to avoid the mass of labels there, which is mostly useless - and really annoying for
         # the backport labels.
         if: |
+          github.event_name != 'workflow_run' &&
           github.event.pull_request.head.repo.owner.login == 'NixOS' && (
             github.head_ref == 'haskell-updates' ||
             github.head_ref == 'python-updates' ||
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index c26160ba8f07d..3b212a18e0e0c 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -7,7 +7,7 @@ on:
   pull_request_target:
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: lint-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}
diff --git a/.github/workflows/review-dismissed.yml b/.github/workflows/review-dismissed.yml
new file mode 100644
index 0000000000000..988b4a47df14b
--- /dev/null
+++ b/.github/workflows/review-dismissed.yml
@@ -0,0 +1,17 @@
+name: Review dismissed
+
+on:
+  pull_request_review:
+    types: [dismissed]
+
+permissions: {}
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  trigger:
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - run: echo This is a no-op only used as a trigger for workflow_run.
diff --git a/.github/workflows/review-submitted.yml b/.github/workflows/review-submitted.yml
new file mode 100644
index 0000000000000..69663054f15b0
--- /dev/null
+++ b/.github/workflows/review-submitted.yml
@@ -0,0 +1,17 @@
+name: Review submitted
+
+on:
+  pull_request_review:
+    types: [submitted]
+
+permissions: {}
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  trigger:
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - run: echo This is a no-op only used as a trigger for workflow_run.
diff --git a/.github/workflows/reviewers.yml b/.github/workflows/reviewers.yml
index 71d0bcb273823..894da05c32e11 100644
--- a/.github/workflows/reviewers.yml
+++ b/.github/workflows/reviewers.yml
@@ -10,14 +10,9 @@ on:
   pull_request_target:
     types: [ready_for_review]
   workflow_call:
-    inputs:
-      caller:
-        description: Name of the calling workflow.
-        required: true
-        type: string
 
 concurrency:
-  group: ${{ inputs.caller }}-${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.run_id }}
+  group: reviewers-${{ github.workflow }}-${{ github.event_name }}-${{ github.event.pull_request.number || github.run_id }}
   cancel-in-progress: true
 
 permissions: {}