Enable auto-merge for bot-created PRs (#22788)

It still needs a human to approve, but now there's one less button to press.

Author: dschuff

.github/workflows/tag-release.yml

@@ -18,28 +18,14 @@ jobs:
         - name: Update Changelog
           run: python3 tools/maint/create_release.py --action
         - name: Create Changelog PR
+          id: cpr
           uses: peter-evans/create-pull-request@v6
           with:
             token: ${{ secrets.EMSCRIPTEN_BOT_TOKEN }}
             title: Mark ${{ env.RELEASE_VERSION }} as released
             team-reviewers: release-reviewers
             delete-branch: true
-        - name: Tag release sha
-          uses: actions/github-script@v7
-          with:
-            github-token: ${{ secrets.EMSCRIPTEN_BOT_TOKEN }}
-            script: |
-              const tag_sha = '${{ inputs.release-sha }}';
-              const release_version = '${{ env.RELEASE_VERSION }}';
-              console.log(`Version ${release_version} at SHA ${tag_sha}`);
-              const regex = /^[0-9]+.[0-9]+.[0-9]+$/;
-              const match = release_version.match(regex);
-              if (!match) {
-                throw new Error('Malformed release version');
-              }
-              await github.rest.git.createRef({
-                owner: context.repo.owner,
-                repo: context.repo.repo,
-                ref: `refs/tags/${release_version}`,
-                sha: tag_sha
-              });
+        - name: Enable auto-merge
+          run: gh pr merge --squash --auto "${{ steps.cpr.outputs.pull-request-number }}"
+          env:
+            GH_TOKEN: ${{ secrets.EMSCRIPTEN_BOT_TOKEN }}