misc: Implement stale action

.github/workflows/stale.yml

@@ -0,0 +1,33 @@
+name: Close stale issues and pull requests
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "30 1 * * *"
+permissions:
+  contents: read
+jobs:
+  stale:
+    permissions:
+      contents: read
+      issues: write
+      pull-requests: write
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          debug-only: true # TODO remove once tested
+          days-before-stale: 90 # default is 60
+          days-before-close: 14 # default is 7
+          exempt-all-assignees: true
+          exempt-draft-pr: true
+          exempt-issue-labels: Keep, InProgress, NeedsTriage
+          exempt-pr-labels: Keep
+          operations-per-run: 100
+          stale-issue-message: >
+            This issue has been marked as stale because there hasn't been any
+            recent activity. It will be closed soon if there are no further
+            updates.
+          stale-pr-message: >
+            This pull request has been marked as stale because there hasn't
+            been any recent activity. It will be closed soon if there are no
+            further updates.