workflow: add close-stalled workflow

.github/workflows/close-stalled.yml

@@ -0,0 +1,34 @@
+name: Close stalled issues and PRs
+on:
+  schedule:
+    - cron: 0 0 * * *
+
+env:
+  CLOSE_MESSAGE: >
+    Closing this because it has stalled. Feel free to reopen if this issue/PR
+    is still relevant, or to ping the collaborator who labelled it stalled if
+    you have any questions.
+
+permissions:
+  contents: read
+
+jobs:
+  stale:
+    permissions:
+      issues: write  # for actions/stale to close stale issues
+      pull-requests: write  # for actions/stale to close stale PRs
+    if: github.repository == 'nodejs/citgm'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@28ca1036281a5e5922ead5184a1bbf96e5fc984e  # v9.0.0
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          days-before-close: 30
+          stale-pr-label: stalled
+          stale-issue-label: stalled
+          close-issue-message: ${{ env.CLOSE_MESSAGE }}
+          close-pr-message: ${{ env.CLOSE_MESSAGE }}
+          # used to filter issues to check whether or not should be closed, avoids hitting maximum operations allowed if needing to paginate through all open issues
+          only-labels: stalled
+          # max requests it will send per run to the GitHub API before it deliberately exits to avoid hitting API rate limits
+          operations-per-run: 500