[OPS] Add GitHub Action to clean-up stale PRs (#1038)

* Add GitHub Action to clean-up stale PRs

* Add token to workflow

Author: vladislav-sidorovich

.github/workflows/stale.yml

@@ -0,0 +1,23 @@
+name: "Close Stale PRs"
+
+on:
+  schedule:
+    - cron: '30 1 * * *' # every day at 1:30 AM
+  workflow_dispatch:
+
+permissions:
+  pull-requests: write
+  issues: write
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          days-before-stale: 35 # 5 working weeks should be ok
+          days-before-close: 14 # plus 2 weeks to act
+          stale-pr-label: 'stale'
+          stale-pr-message: 'This PR is stale because it has been open 35 days with no activity. Remove "stale" label or comment or this will be closed in 14 days.'
+          close-pr-message: 'This PR was closed because it has been stalled for 14 days with no activity.'