Enable CodeQL weekly scan

Author: andyleejordan

.github/workflows/codeql-analysis.yml

@@ -7,6 +7,8 @@ on:
     # The branches below must be a subset of the branches above
     branches: [ main ]
     paths-ignore: [ '**/*.md' ]
+  schedule:
+    - cron: '25 9 * * 0'
 
 jobs:
   analyze: