Add stale workflow

Author: mathieucarbou

.github/workflows/stale.yaml

@@ -0,0 +1,24 @@
+name: "Close stale issues and PRs"
+on:
+  schedule:
+    - cron: "30 1 * * *"
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          stale-issue-message: "This issue is stale because it has been open 30 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 30 days with no activity. Remove stale label or comment or this will be closed in 7 days."
+          close-issue-message: "This issue was closed because it has been stalled for 7 days with no activity."
+          close-pr-message: "This PR was closed because it has been stalled for 7 days with no activity."
+          days-before-issue-stale: 30
+          days-before-pr-stale: 30
+          days-before-issue-close: 7
+          days-before-pr-close: 7
+
+permissions:
+  # contents: write # only for delete-branch option
+  issues: write
+  pull-requests: write