Set up workflow tracking stale issues.

Author: chungyc

.github/workflows/stale.yml

@@ -0,0 +1,33 @@
+# This workflow warns and then closes issues and PRs that have had no activity for a specified amount of time.
+#
+# You can adjust the behavior by modifying this file.
+# For more information, see:
+# https://github.com/actions/stale
+name: Track Stale Issues
+
+on:
+  schedule:
+  - cron: '33 6 * * *'
+
+permissions: read-all
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+      pull-requests: write
+
+    steps:
+    - uses: actions/stale@v5
+      with:
+        days-before-stale: 90
+        days-before-close: 30
+        stale-issue-message: 'No activity with issue for 90 days.'
+        stale-pr-message: 'No activity with pull request for 90 days.'
+        stale-issue-label: 'stale'
+        stale-pr-label: 'stale'
+        close-issue-message: 'No activity for 120 days.  Will not fix.'
+        close-pr-message: 'No activity for 120 days.  Will not merge.'
+        close-issue-label: 'wontfix'
+        close-pr-label: 'wontfix'