fix: add return type annotation

Signed-off-by: orertrr <[email protected]>

module/users.py

@@ -426,7 +426,7 @@ def marshal_dietary_habit(user_infos: dict[str, Any]) -> Generator[dict[str, Any
             yield data
 
     @staticmethod
-    def get_dietary_habit_statistics(uids: list[str]):
+    def get_dietary_habit_statistics(uids: list[str]) -> dict[str, int]:
         ''' Get dietary habit statistics by given uids '''
         result: dict[str, int] = { }