Drop asynctest (#44746)

tests/components/plex/test_server.py

@@ -1,5 +1,6 @@
 """Tests for Plex server."""
 import copy
+from unittest.mock import patch
 
 from plexapi.exceptions import BadRequest, NotFound
 from requests.exceptions import ConnectionError, RequestException
@@ -39,8 +40,6 @@ from .mock_classes import (
     MockPlexShow,
 )
 
-from tests.async_mock import patch
-
 
 async def test_new_users_available(hass, entry, mock_websocket, setup_plex_server):
     """Test setting up when new users available on Plex server."""