Drop asynctest (#44746)

tests/scripts/test_check_config.py

@@ -1,12 +1,12 @@
 """Test check_config script."""
 import logging
+from unittest.mock import patch
 
 import pytest
 
 from homeassistant.config import YAML_CONFIG_FILE
 import homeassistant.scripts.check_config as check_config
 
-from tests.async_mock import patch
 from tests.common import get_test_config_dir, patch_yaml_files
 
 _LOGGER = logging.getLogger(__name__)