ci: add actions language to CodeQL workflow, disable default setup

Author: mnriem

.github/workflows/codeql.yml

@@ -16,7 +16,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        language: [ 'python' ]
+        language: [ 'actions', 'python' ]
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4