Fix HA websocket keepalive fallback

tests/test_main.py

@@ -61,12 +61,16 @@ def test_ha_event_listener_processes_state_change(tmp_path: Path) -> None:
             ]
         )
 
-        with patch("websockets.connect", return_value=fake_ws):
+        with patch("websockets.connect", return_value=fake_ws) as connect:
             try:
                 await _ha_event_listener(mock_app, mock_client)
             except asyncio.CancelledError:
                 pass
 
+        connect.assert_called_once_with(
+            "ws://homeassistant:8123/api/websocket",
+            ping_interval=None,
+        )
         assert fake_ws.sent == [
             {"type": "auth", "access_token": "test-token"},
             {"id": 1, "type": "subscribe_events", "event_type": "state_changed"},