close stale issues after 30 days

.github/workflows/stale.yml

@@ -0,0 +1,20 @@
+name: 'Close stale issues'
+on:
+  schedule:
+    - cron: '30 1 * * *'
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v6
+        with:
+          days-before-stale: 30
+          days-before-pr-stale: -1
+          days-before-close: 7
+          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-issue-label: 'stale issue'
+          exempt-issue-labels: 'good first issue, WIP, question, up for grabs'