Update pull_request.yml

Author: MaxDesiatov

.github/workflows/pull_request.yml

@@ -18,7 +18,7 @@ jobs:
     with:
       license_header_check_project_name: "Swift"
       api_breakage_check_enabled: false
-      unacceptable_language_check_enabled: false
+      unacceptable_language_check_enabled: true
       license_header_check_enabled: false
       broken_symlink_check_enabled: false
       format_check_enabled: false