ci: Greenlight MELPA releases after successfully publishing binaries

Author: ubolonton

.github/workflows/bump-version.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Bump version
         run: script/dev bump-version
 
-      # This will not trigger workflows, because it doesn't use a personal access token.
+      # We don't want this to trigger workflows, so we don't use a personal access token.
       - name: Create the release commit
         # TODO: Sign the tag?
         run: |

.github/workflows/release.yml

@@ -81,7 +81,9 @@ jobs:
       - uses: actions/checkout@v2
       - name: Generate release notes
         run: |
-          script/dev release-notes "$(git describe --tags --abbrev=0)" > RELEASE-NOTES
+          RELEASE_VERSION=$(git describe --tags --abbrev=0)
+          script/dev release-notes "$RELEASE_VERSION" > RELEASE-NOTES
+          echo RELEASE_VERSION=$RELEASE_VERSION >> $GITHUB_ENV
           cat RELEASE-NOTES
 
       - name: Download binaries
@@ -96,3 +98,21 @@ jobs:
           body_path: RELEASE-NOTES
           files: |
             tree-sitter-grammars-*.tar.gz
+
+      - name: Greenlight releasing to MELPA
+        run: |
+          git push origin ${{ env.RELEASE_VERSION }}:refs/heads/release
+        continue-on-error: true
+
+      # We don't want this to trigger workflows, so we don't use a personal access token.
+      - name: Greenlight releasing to MELPA Stable
+        uses: actions/github-script@v4
+        with:
+          script: |
+            github.git.createRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: "refs/tags/melpa-stable/v${{ env.RELEASE_VERSION }}",
+              sha: context.sha
+            })
+        continue-on-error: true