Fix zeroconf tests with cython 3 (#97054)

tests/conftest.py

@@ -1104,23 +1104,34 @@ def mock_get_source_ip() -> Generator[None, None, None]:
 @pytest.fixture
 def mock_zeroconf() -> Generator[None, None, None]:
     """Mock zeroconf."""
+    from zeroconf import DNSCache  # pylint: disable=import-outside-toplevel
+
     with patch(
         "homeassistant.components.zeroconf.HaZeroconf", autospec=True
     ) as mock_zc, patch(
         "homeassistant.components.zeroconf.HaAsyncServiceBrowser", autospec=True
     ):
+        zc = mock_zc.return_value
+        # DNSCache has strong Cython type checks, and MagicMock does not work
+        # so we must mock the class directly
+        zc.cache = DNSCache()
         yield mock_zc
 
 
 @pytest.fixture
 def mock_async_zeroconf(mock_zeroconf: None) -> Generator[None, None, None]:
     """Mock AsyncZeroconf."""
+    from zeroconf import DNSCache  # pylint: disable=import-outside-toplevel
+
     with patch("homeassistant.components.zeroconf.HaAsyncZeroconf") as mock_aiozc:
         zc = mock_aiozc.return_value
         zc.async_unregister_service = AsyncMock()
         zc.async_register_service = AsyncMock()
         zc.async_update_service = AsyncMock()
         zc.zeroconf.async_wait_for_start = AsyncMock()
+        # DNSCache has strong Cython type checks, and MagicMock does not work
+        # so we must mock the class directly
+        zc.zeroconf.cache = DNSCache()
         zc.zeroconf.done = False
         zc.async_close = AsyncMock()
         zc.ha_async_close = AsyncMock()