Fix quantum_gateway tests (#168610)

tests/components/quantum_gateway/conftest.py

@@ -6,6 +6,16 @@ from unittest.mock import AsyncMock, patch
 import pytest
 
 
+@pytest.fixture
+def hass_config_dir(hass_tmp_config_dir: str) -> str:
+    """Use temporary config directory for device_tracker tests.
+
+    This fixture can be removed when the legacy YAML writing has been removed
+    from the device tracker integration.
+    """
+    return hass_tmp_config_dir
+
+
 @pytest.fixture
 async def mock_scanner() -> Generator[AsyncMock]:
     """Mock QuantumGatewayScanner instance."""