Add workflow (#470)

* Add workflow

* Bump number of days

.github/workflows/stale_prs.yml

@@ -0,0 +1,22 @@
+name: Close stale issues
+on:
+  schedule:
+    - cron: "30 1 * * *"
+
+jobs:
+  close-issues:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+    steps:
+      - uses: actions/[email protected]
+        with:
+          days-before-issue-stale: 35
+          days-before-issue-close: 7
+          stale-issue-label: "stale"
+          stale-issue-message: "This issue has been marked as stale because it has been open for 7 days with no activity."
+          close-issue-message: "This issue was closed because there has been no activity since being marked as stale."
+          days-before-pr-stale: -1
+          days-before-pr-close: -1
+          repo-token: ${{ secrets.GITHUB_TOKEN }}