lk.transcription_final attribute is never "true" in the TTS transcription

[brianzaubar]

The TTS "lk.transcription" stream never returns true in the lk.transcription_final attribute.

We are using these packages:

• livekit-client@2.11.4
• livekit-agent@1.0.20

[longcw]

For agent transcription, lk.transcription_final attribute is set to true when the stream closed. You can read it after text stream closed.

Basically for agent transcription, it's streamed as delta so every text stream is final. The final flag is mainly for the user transcription which may be interim result that may be overwritten by the new message.