Use shallow copy for faster loading

server.py

@@ -395,7 +395,7 @@ class LeaderboardServer:
         if pre_submit == None:
             category = category if category else self.TASKS_CATEGORY_OVERALL
             with self.var_lock.ro:
-                return copy.deepcopy(self.leaderboard_dataframes[category])
+                return copy.copy(self.leaderboard_dataframes[category])
         else:
             return self._get_leaderboard(pre_submit=pre_submit, category=category)