event: tts_message_end always return in api streaming response_mode

[xmenw]

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Dify version

0.8.3

Cloud or Self Hosted

Cloud

Steps to reproduce

curl --location 'https://api.dify.ai/v1/chat-messages'
--header 'Authorization: Bearer app-PqAVQAqIr7VJgxQTN3pIa9Oe'
--header 'Content-Type: application/json'
--data '{
"inputs": {},
"query": "What are the specs of the iPhone 13 Pro Max?",
"response_mode": "streaming",
"conversation_id": "",
"user": "abc-123"
}'

✔️ Expected Behavior

This parameter is not returned if text_to_speech is not configured and disable is enabled

❌ Actual Behavior

[dosubot]

Hey @xmenw! I'm here to help you with any bugs, questions, or contributions you have for Dify. I can assist you while you wait for a human maintainer. Ask me anything!

The "tts_message_end" event always returns in the API streaming response_mode even when text_to_speech is not configured and disabled because it is a predefined event in the streaming response structure. This event is used to indicate the end of the audio stream, and its presence in the response does not depend on the actual configuration of text_to_speech ^[1].

To continue talking to Dosu, mention @dosu.

[crazywoola]

@ic-xu Could you take a look at this.

[ic-xu]

@ic-xu你能看看这个吗？

OK, I'll just filter it.

[ic-xu]

PR. #8846