Merge pull request #25 from dpc-sdp/feature/stale-prs

[R20-1997] stale prs workflow

.github/workflows/stale.yml

@@ -0,0 +1,19 @@
+name: Stale PRs
+
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          days-before-pr-stale: 60
+          days-before-pr-close: 7
+          stale-pr-message: 'This PR has been automatically marked as stale, it will be closed if no further activity occurs.'
+          close-pr-message: 'This PR was automatically closed due to inactivity.'
+          stale-pr-label: 'Stale'
+          exempt-pr-labels: 'Permanent'