Merge branch 'fix/fork-spec-mysql' into 'master'

Fix fork_spec failure to do with mySQL

Closes #31870

See merge request !11121

lib/gitlab/import_export/import_export.yml

@@ -85,6 +85,8 @@ excluded_attributes:
     - :id
     - :star_count
     - :last_activity_at
+    - :last_repository_updated_at
+    - :last_repository_check_at
     - :mirror_last_update_at
     - :mirror_last_successful_update_at
     - :mirror_user_id