Make DHCP discovery aware of the network integration (#144767)

Co-authored-by: J. Nick Koston <nick@koston.org>

tests/components/dhcp/test_websocket_api.py

@@ -22,6 +22,7 @@ async def test_subscribe_discovery(
 
     async def mock_start(
         callback: Callable[[aiodhcpwatcher.DHCPRequest], None],
+        if_indexes: list[int] | None = None,
     ) -> None:
         """Mock start."""
         nonlocal saved_callback