See if this makes loop available.

tests/test_cluster.py

@@ -1,4 +1,6 @@
 import unittest
+
+import pytest
 from aiokafka.cluster import ClusterMetadata
 from aiokafka.protocol.metadata import MetadataResponse
 from tests._testutil import run_until_complete
@@ -22,6 +24,7 @@ def test_empty_broker_list():
     )
     assert len(cluster.brokers()) == 2
 
+@pytest.mark.usefixtures("setup_test_class_serverless")
 class TestClusterMetadata(unittest.TestCase):
     @run_until_complete
     async def test_request_update(self):