Check mr title for invalid characters

kibot-ci.yml

@@ -102,9 +102,11 @@ image:
 
   git_tag: 
     - |
-      if [[ $GITLAB_CI == 'true' && $CI_COMMIT_BRANCH == "main" ]]; then
+      if [[ $GITLAB_CI == 'true' && $CI_COMMIT_BRANCH == "main" ]]; then 
         echo "running git tag"
         git tag $CI_COMMIT_MESSAGE
+      elif [[ $CI_PIPELINE_SOURCE == "merge_request_event" && $CI_MERGE_REQUEST_TARGET_BRANCH_NAME == "main" && "$CI_MERGE_REQUEST_TITLE" =~ [^a-zA-Z0-9.-_] ]]; then
+        exit 1
       fi
 
   merge_libs: