chore: adjust stale issues workflow schedule to run at 2:00 AM UTC (#1195)

Author: tangcent

.github/workflows/stale.yml

@@ -1,7 +1,7 @@
 name: 'Close stale issues'
 on:
   schedule:
-    - cron: '0 0 * * *'  # Run daily at midnight
+    - cron: '0 2 * * *'  # Run daily at 2:00 AM UTC
   workflow_dispatch:  # Allow manual triggering
 
 jobs: