Fix: change default group task list to empty

lm_eval/tasks/__init__.py

@@ -333,7 +333,7 @@ def _get_task_and_group(self, task_dir: str):
                         # This is a group config
                         tasks_and_groups[config["group"]] = {
                             "type": "group",
-                            "task": -1,  # This signals that
+                            "task": [],  # This signals that
                             # we don't need to know
                             # the task list for indexing
                             # as it can be loaded