Use the shared zeroconf instance when attempting to create another Zeroconf instance (#38744)

tests/components/zeroconf/test_init.py

@@ -1,5 +1,4 @@
 """Test Zeroconf component setup process."""
-import pytest
 from zeroconf import InterfaceChoice, IPVersion, ServiceInfo, ServiceStateChange
 
 from homeassistant.components import zeroconf
@@ -22,13 +21,6 @@ HOMEKIT_STATUS_UNPAIRED = b"1"
 HOMEKIT_STATUS_PAIRED = b"0"
 
 
-@pytest.fixture
-def mock_zeroconf():
-    """Mock zeroconf."""
-    with patch("homeassistant.components.zeroconf.HaZeroconf") as mock_zc:
-        yield mock_zc.return_value
-
-
 def service_update_mock(zeroconf, services, handlers):
     """Call service update handler."""
     for service in services: