feat: consolidate release CI, dedup release and PR

Author: nyurik

.github/workflows/ci.yml

@@ -9,6 +9,10 @@ on:
     types: [ published ]
   workflow_dispatch:
 
+permissions:
+  pull-requests: write
+  contents: write
+
 defaults:
   run:
     shell: bash
@@ -189,9 +193,43 @@ jobs:
   # This job checks if any of the previous jobs failed or were canceled.
   # This approach also allows some jobs to be skipped if they are not needed.
   ci-passed:
-    if: always()
     needs: [ test, test-msrv, build, cross-build ]
+    if: always()
     runs-on: ubuntu-latest
     steps:
       - if: ${{ contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled') }}
         run: exit 1
+
+  # Release unpublished packages or create a PR with changes
+  release-plz:
+    needs: [ ci-passed ]
+    if: |
+      always()
+      && needs.ci-passed.result == 'success'
+      && github.event_name == 'push'
+      && github.ref == 'refs/heads/main'
+      && github.repository_owner == 'nyurik'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+    concurrency:
+      group: release-plz-${{ github.ref }}
+      cancel-in-progress: false
+    steps:
+      - uses: actions/checkout@v4
+        with: { fetch-depth: 0 }
+      - uses: dtolnay/rust-toolchain@stable
+      - name: Publish to crates.io if crate's version is newer
+        uses: release-plz/[email protected]
+        id: release
+        with: { command: release }
+        env:
+          GITHUB_TOKEN: ${{ secrets.RELEASE_PLZ_TOKEN }}
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
+      - name: If version is the same, create a PR proposing new version and changelog for the next release
+        uses: release-plz/[email protected]
+        if: ${{ steps.release.outputs.releases_created == 'false' }}
+        with: { command: release-pr }
+        env:
+          GITHUB_TOKEN: ${{ secrets.RELEASE_PLZ_TOKEN }}