fix cpu test

Author: erictang000

tests/backends/skyrl_train/distributed/test_megatron_correctness.py

@@ -163,7 +163,7 @@ async def test_non_colocated_pause_before_broadcast(self):
         dispatch._inference_engine_client = AsyncMock()
         dispatch._inference_engine_client.pause_generation = AsyncMock(side_effect=lambda: call_order.append("pause"))
         dispatch._inference_engine_client.resume_generation = AsyncMock(side_effect=lambda: call_order.append("resume"))
-        dispatch._broadcast_to_inference_engines = MagicMock(side_effect=lambda _: call_order.append("broadcast"))
+        dispatch._broadcast_to_inference_engines = MagicMock(side_effect=lambda *args, **kwargs: call_order.append("broadcast"))
         dispatch._prepare_for_weight_sync = MagicMock()
         dispatch._finish_weight_sync = MagicMock()