misc(ci) add stalebot

.github/workflows/stale.yml

@@ -0,0 +1,21 @@
+name: 'Close stale issues and PRs'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v8
+        with:
+          stale-issue-message: 'This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.'
+          stale-pr-message: 'This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.'
+          stale-issue-label: 'stale'
+          stale-pr-label: 'stale'
+          exempt-issue-labels: 'confirmed'
+          exempt-pr-labels: 'confirmed'
+          days-before-issue-stale: 60
+          days-before-pr-stale: 90
+          days-before-issue-close: 10
+          days-before-pr-close: 10