Remove duplicated pytest decorator pair introduced in merge

Author: chenlichao

tests/lib/streaming/test_messages.py

@@ -664,8 +664,6 @@ async def test_refusal_stop_details_propagated(self, respx_mock: MockRouter) ->
         ) as stream:
             assert_refusal_response(await stream.get_final_message())
 
-    @pytest.mark.asyncio
-    @pytest.mark.respx(base_url=base_url)
     @pytest.mark.asyncio
     @pytest.mark.respx(base_url=base_url)
     async def test_message_delta_fields_propagated(self, respx_mock: MockRouter) -> None: