Fix test RuntimeWarning for upb (#122325)

tests/components/upb/test_config_flow.py

 """Test the UPB Control config flow."""
 
 from asyncio import TimeoutError
-from unittest.mock import AsyncMock, PropertyMock, patch
+from unittest.mock import AsyncMock, MagicMock, PropertyMock, patch
 
 from homeassistant import config_entries
 from homeassistant.components.upb.const import DOMAIN
@@ -18,6 +18,7 @@ def mocked_upb(sync_complete=True, config_ok=True):
     upb_mock = AsyncMock()
     type(upb_mock).network_id = PropertyMock(return_value="42")
     type(upb_mock).config_ok = PropertyMock(return_value=config_ok)
+    type(upb_mock).disconnect = MagicMock()
     if sync_complete:
         upb_mock.async_connect.side_effect = _upb_lib_connect
     return patch(