chore: add stale bot [bot-pr] (#540)

Author: cloud-foundation-bot

.github/workflows/stale.yml

@@ -0,0 +1,15 @@
+name: "Close stale issues"
+on:
+  schedule:
+  - cron: "0 23 * * *"
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/stale@v3
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        stale-issue-message: 'This issue is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 7 days'
+        stale-pr-message: 'This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 7 days'
+        exempt-issue-labels: triaged