Drop asynctest (#44746)

tests/components/wemo/entity_test_helpers.py

@@ -4,6 +4,7 @@ This is not a test module. These test methods are used by the platform test modu
 """
 import asyncio
 import threading
+from unittest.mock import patch
 
 from homeassistant.components.homeassistant import (
     DOMAIN as HA_DOMAIN,
@@ -13,8 +14,6 @@ from homeassistant.const import ATTR_ENTITY_ID, STATE_OFF, STATE_UNAVAILABLE
 from homeassistant.core import callback
 from homeassistant.setup import async_setup_component
 
-from tests.async_mock import patch
-
 
 def _perform_registry_callback(hass, pywemo_registry, pywemo_device):
     """Return a callable method to trigger a state callback from the device."""