Drop asynctest (#44746)

tests/components/folder_watcher/test_init.py

@@ -1,11 +1,10 @@
 """The tests for the folder_watcher component."""
 import os
+from unittest.mock import Mock, patch
 
 from homeassistant.components import folder_watcher
 from homeassistant.setup import async_setup_component
 
-from tests.async_mock import Mock, patch
-
 
 async def test_invalid_path_setup(hass):
     """Test that an invalid path is not set up."""