Fix some more usages of asynctest (#39570)

tests/components/deconz/test_config_flow.py

@@ -1,7 +1,6 @@
 """Tests for deCONZ config flow."""
 import asyncio
 
-from asynctest.mock import patch
 import pydeconz
 
 from homeassistant import data_entry_flow
@@ -22,6 +21,8 @@ from homeassistant.const import CONF_API_KEY, CONF_HOST, CONF_PORT
 
 from .test_gateway import API_KEY, BRIDGEID, setup_deconz_integration
 
+from tests.async_mock import patch
+
 
 async def test_flow_discovered_bridges(hass, aioclient_mock):
     """Test that config flow works for discovered bridges."""