Add GHA workflow to mark and close inactive PRs and Issues

.github/workflows/close-inactive.yaml

@@ -0,0 +1,30 @@
+name: Close inactive issues and PRs
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: "30 1 * * *"
+
+jobs:
+  close-stale:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - uses: actions/stale@v3
+        with:
+          days-before-stale: 30
+          days-before-close: 14
+          stale-issue-label: "stale"
+          stale-pr-label: "stale"
+
+          exempt-issue-labels: backlog,triage,nostale
+          exempt-pr-labels: backlog,triage,nostale
+
+          stale-pr-message: "This PR is stale because it has been open for 30 days with no activity."
+          close-pr-message: "This PR was closed because it has been inactive for 14 days since being marked as stale."
+
+          stale-issue-message: "This issue is stale because it has been open for 30 days with no activity."
+          close-issue-message: "This issue was closed because it has been inactive for 14 days since being marked as stale."
+
+          repo-token: ${{ secrets.GITHUB_TOKEN }}