workflows/pkg-installer: create an issue when publish fails

This uses the `Homebrew/actions/create-or-update-issue` action added in
Homebrew/actions#588 to create an issue when the publish fails for a
release. It also automatically updates the issue on repeated failures,
and closes the issue when the latest workflow run succeeds.

.github/workflows/pkg-installer.yml

@@ -213,3 +213,29 @@ jobs:
         run: gh release upload --repo Homebrew/brew
                                 "${GITHUB_REF//refs\/tags\//}"
                                 "${{ needs.build.outputs.installer_path }}"
+
+  issue:
+    needs: [build, test, upload]
+    if: always() && github.event_name == 'release'
+    runs-on: ubuntu-latest
+    env:
+      RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+    permissions:
+      # To create or update issues
+      issues: write
+    steps:
+      - name: Open, update, or close pkg installer issue
+        uses: Homebrew/actions/create-or-update-issue@master
+        with:
+          title: Failed to publish pkg installer
+          body: >
+            The pkg installer workflow [failed](${{ env.RUN_URL }}) for release
+            ${{ github.ref_name }}. No pkg installer was uploaded to the GitHub
+            release.
+          labels: bug,release blocker
+          update-existing: ${{ contains(needs.*.result, 'failure') }}
+          close-existing: ${{ needs.upload.result == 'success' }}
+          close-from-author: github-actions[bot]
+          close-comment: >
+            The pkg installer workflow [succeeded](${{ env.RUN_URL }}) for
+            release ${{ github.ref_name }}. Closing this issue.