Fix tests for Python 3.8 (#34672)

tests/conftest.py

@@ -1,8 +1,8 @@
 """Set up some common test helper things."""
 import functools
 import logging
-from unittest.mock import patch
 
+from asynctest import patch
 import pytest
 import requests_mock as _requests_mock
 
@@ -26,7 +26,6 @@ from tests.common import (  # noqa: E402, isort:skip
     INSTANCES,
     MockUser,
     async_test_home_assistant,
-    mock_coro,
     mock_storage as mock_storage,
 )
 from tests.test_util.aiohttp import mock_aiohttp_client  # noqa: E402, isort:skip
@@ -128,7 +127,7 @@ def mock_device_tracker_conf():
         side_effect=mock_update_config,
     ), patch(
         "homeassistant.components.device_tracker.legacy.async_load_config",
-        side_effect=lambda *args: mock_coro(devices),
+        side_effect=lambda *args: devices,
     ):
         yield devices