Run CI on self-hosted runners

Mirror QuantConnect/Lean#9540 (commit c57fd18b): run the build/test workflow on
self-hosted runners directly inside a job-level quantconnect/lean:foundation
container (--cpus 12 --memory 12g) instead of the GitHub-hosted ubuntu runner +
addnab/docker-run wrapper. Drops the disk-cleanup step and the docker-run wrapper
(build/test now run as a normal step inside the container; secrets via container
env), and adds a concurrency group (cancel-in-progress).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: Martin-Molinero

.github/workflows/build.yml

@@ -6,21 +6,20 @@ on:
   pull_request:
     branches: [master]
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   build:
-    runs-on: ubuntu-24.04
+    runs-on: self-hosted
+    container:
+        image: quantconnect/lean:foundation
+        options: --cpus 12 --memory 12g
     steps:
       - name: Checkout
         uses: actions/checkout@v2
 
-      - name: Liberate disk space
-        uses: jlumbroso/free-disk-space@main
-        with:
-          tool-cache: true
-          large-packages: false
-          docker-images: false
-          swap-storage: false
-
       - name: Checkout Lean Same Branch
         id: lean-same-branch
         uses: actions/checkout@v2
@@ -40,15 +39,12 @@ jobs:
       - name: Move Lean
         run: mv Lean ../Lean
 
-      - uses: addnab/docker-run-action@v3
-        with:
-          image: quantconnect/lean:foundation
-          options: --workdir /__w/Lean.DataSource.SDK/Lean.DataSource.SDK -v /home/runner/work:/__w
-          shell: bash
-          run: |
-            # BuildDataSource
-            dotnet build ./QuantConnect.DataSource.csproj /p:Configuration=Release /v:quiet /p:WarningLevel=1 && \
-            # BuildTests
-            dotnet build ./tests/Tests.csproj /p:Configuration=Release /v:quiet /p:WarningLevel=1 && \
-            # Run Tests
-            dotnet test ./tests/bin/Release/net9.0/Tests.dll
+      - name: Run build and tests
+        run: |
+          # BuildDataSource
+          dotnet build ./QuantConnect.DataSource.csproj /p:Configuration=Release /v:quiet /p:WarningLevel=1 && \
+          # BuildTests
+          dotnet build ./tests/Tests.csproj /p:Configuration=Release /v:quiet /p:WarningLevel=1 && \
+          # Run Tests
+          dotnet test ./tests/bin/Release/net9.0/Tests.dll
+