ci: adds failed validation test to CI

.gitlab-ci.yml

@@ -8,6 +8,8 @@ validate_merge_request_source_branch:
   stage: validate
   script:
     - echo "Job runs to validate merge request source branch"
+    - echo "Testing failed validation"
+    - exit 1
   rules:
     - if: $CI_PIPELINE_SOURCE == 'merge_request_event' && $CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "master"
     - if: $CI_PIPELINE_SOURCE == 'merge_request_event' && $CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "main"