fix(sup-1998): only cast CategoryList once per job (#1830)

Co-authored-by: Nicolas Hervé <[email protected]>

Author: HNicolas

src/kili/services/label_data_parsing/job_response.py

@@ -33,7 +33,9 @@ def __init__(self, job_name: str, project_info: Project, job_payload: Dict) -> N
         self._job_interface = project_info["jsonInterface"][job_name]  # type: ignore
 
         # cast lists to objects
-        if "categories" in self._json_data:
+        if "categories" in self._json_data and not isinstance(
+            self._json_data["categories"], category_module.CategoryList
+        ):
             self._json_data["categories"] = category_module.CategoryList(
                 job_name=self._job_name,
                 project_info=self._project_info,