Adjust schedule for keepalive workflow

.github/workflows/keepalive.yml

@@ -1,7 +1,7 @@
 name: Prevent github from suspending scheduled actions
 on:
   schedule:
-    - cron: "0 3 1 * *"
+    - cron: "0 0 * * 3"
   workflow_dispatch:
 permissions:
   contents: write