Checkout kn-main aws-kotlin-repo-tools

Author: lauzadis

.github/actions/setup-build/action.yml

@@ -10,6 +10,7 @@ runs:
       with:
         path: 'aws-kotlin-repo-tools'
         repository: 'awslabs/aws-kotlin-repo-tools'
+        ref: 'kn-main'
         sparse-checkout: |
           .github