Fix default branch name in CodeQL workflow

Author: evgenyz

.github/workflows/codeql.yml

@@ -2,7 +2,7 @@ name: "CodeQL"
 
 on:
   push:
-    branches: [ 'maint-1.3', 'maint-1.2', 'master' ]
+    branches: [ 'maint-1.3', 'maint-1.2', 'main' ]
   pull_request:
     # The branches below must be a subset of the branches above
     branches: [ 'maint-1.3' ]