Automatically marks PRs and issues stale (#7675)

Marks PRs and issues with the Stale tag and makes a comment on the PR and issue.
In debug mode for now.

.github/workflows/stale.yml

@@ -0,0 +1,27 @@
+name: Mark stale issues and pull requests
+
+on:
+  push:
+    paths:
+      - .github/workflows/stale.yml
+  schedule:
+  - cron: "30 1 * * *"
+
+jobs:
+  stale:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/stale@v3
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        stale-issue-message: 'This issue has been automatically marked as stale because it has not had recent activity. Marking it stale to flag it for further consideration by the community.'
+        stale-pr-message: 'This pull request has been automatically marked as stale because it has not had recent activity. Marking it stale to flag it for further consideration by the community.'
+        stale-issue-label: 'Stale'
+        stale-pr-label: 'Stale'
+        days-before-pr-stale: 90
+        days-before-issue-stale: 365
+        days-before-pr-close: -1
+        days-before-issue-close: -1
+        debug-only: true