Add missing return type in test __init__ methods (#123932)

* Add missing return type in test __init__ methods

* Adjust

tests/components/websocket_api/test_commands.py

@@ -920,7 +920,7 @@ async def test_subscribe_entities_with_unserializable_state(
     class CannotSerializeMe:
         """Cannot serialize this."""
 
-        def __init__(self):
+        def __init__(self) -> None:
             """Init cannot serialize this."""
 
     hass.states.async_set("light.permitted", "off", {"color": "red"})