Revert "Remove redundant CRON."

This reverts commit 2d2249e.

Author: Scott Straughan

.github/workflows/codeql.yml

@@ -5,6 +5,8 @@ on:
     branches: [ 'main' ]
   pull_request:
     branches: [ 'main' ]
+  schedule:
+    - cron: '31 11 * * 2'
 
 permissions: read-all