Add cleanup CI

Author: jeroen

.github/workflows/stale.yml

@@ -0,0 +1,29 @@
+name: 'Close stale issues and PRs'
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '30 1 * * *'
+
+permissions:
+  issues: write
+  pull-requests: write
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          days-before-stale: 365
+          days-before-close: 1
+          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. If the
+            problem still exists in the latest version, feel free to raise it again
+            in a new issue. Please remember to keep the description terse and include
+            a minimal example to help us look into it.
+          stale-pr-message: >
+            This pull request has been automatically marked as stale because it has not had
+            recent activity. It will be closed if no further activity occurs.
+          exempt-all-assignees: true
+          operations-per-run: 1000