Use trusted publishing for publishing to crates.io

The publishing is done from a different workflow than the release
to ensure that the publishing only happens after we the draft release
created by the release workflow is published on github.

Author: bjorn3

.github/workflows/publish-crates-io.yml

@@ -0,0 +1,21 @@
+name: Publish to crates.io
+
+on:
+  release:
+    types: [released] # only when creating a full release (not pre-release or draft)
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+
+    environment: publish
+    permissions:
+      id-token: write
+
+    steps:
+    - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+    - uses: rust-lang/crates-io-auth-action@b7e9a28eded4986ec6b1fa40eeee8f8f165559ec # v1.0.3
+      id: auth
+    - run: cargo publish
+      env:
+        CARGO_REGISTRY_TOKEN: ${{ steps.auth.outputs.token }}