build: close stalled issues and PRs with github action

This introduces a GitHub Action workflow to close issues and PRs
which has been labelled `stalled` 30 days ago (or more).

`stale` labelling and unlabelling of issues and PRs are still done
manually by collaborators.

Refs nodejs/github-bot#261

PR-URL: #34555
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Mary Marchini <oss@mmarchini.me>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Zeyu Yang <himself65@outlook.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Shelley Vohr <codebytere@gmail.com>

.github/workflows/close-stalled.yml

@@ -0,0 +1,21 @@
+name: Close stalled issues and PRs
+on:
+  schedule:
+  - cron: "0 0 * * *"
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/stale@v3
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        days-before-close: 30
+        stale-pr-label: stalled
+        stale-issue-label: stalled
+        close-issue-message: Closing this because it has stalled. Feel free to reopen if this issue is still relevant, or to ping the collaborator who labelled it stalled if you have any questions.
+        close-pr-message: Closing this because it has stalled. Feel free to reopen if this PR is still relevant, or to ping the collaborator who labelled it stalled if you have any questions.
+        # deactivates automatic removal of stalled label if issue gets any activity
+        remove-stale-when-updated: false
+        # deactivates automatic stale labelling as we prefer to do that manually
+        days-before-stale: -1