docs: openai#1999 adjust the realtime module code comment (openai#2000)

Author: seratch

src/agents/realtime/openai_realtime.py

@@ -629,8 +629,9 @@ async def _handle_ws_event(self, event: dict[str, Any]):
  )
  if not automatic_response_cancellation_enabled:
  await self._cancel_response()
- # Avoid sending conversation.item.truncate here; when GA is set to
- # interrupt on VAD start, the server will handle truncation.
+ # Avoid sending conversation.item.truncate here. When the session's
+ # turn_detection.interrupt_response is enabled (GA default), the server emits
+ # conversation.item.truncated after the VAD start and takes care of history updates.
  elif parsed.type == "response.created":
  self._ongoing_response = True
  await self._emit_event(RealtimeModelTurnStartedEvent())