Fix pytest warning (#2577)

Author: pquentin

test_elasticsearch/test_async/test_server/conftest.py

@@ -26,9 +26,7 @@
 
 
 @pytest_asyncio.fixture(scope="function")
-@pytest.mark.usefixtures("sync_client")
 async def async_client(elasticsearch_url):
-    # 'sync_client' fixture is used for the guaranteed wipe_cluster() call.
 
     if not hasattr(elasticsearch, "AsyncElasticsearch"):
         pytest.skip("test requires 'AsyncElasticsearch' and aiohttp to be installed")