fix(livekit): remove redundant self arg in on_call_state_updated event

_on_call_state_updated passes (self, state) to _call_event_handler,
but _run_handler already prepends self when invoking the handler.
This causes handlers to receive 3 positional arguments instead of 2,
making the on_call_state_updated event unusable.

This aligns with how _on_first_participant_joined correctly passes
only the data arg without self.

src/pipecat/transports/livekit/transport.py

@@ -1244,7 +1244,7 @@ class LiveKitTransport(BaseTransport):
 
     async def _on_call_state_updated(self, state: str):
         """Handle call state update events."""
-        await self._call_event_handler("on_call_state_updated", self, state)
+        await self._call_event_handler("on_call_state_updated", state)
 
     async def _on_first_participant_joined(self, participant_id: str):
         """Handle first participant joined events."""