[Bug]: When the modalities parameter of an inference request is configured as audio, only audio should be returned in the inference results.

[yenuo26]

Your current environment

The output of python collect_env.py

Your output of `python collect_env.py` here

🐛 Describe the bug

vllm project #540

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[amy-why-3459]

@lisihao

[zengchuang-hw]

已自验证修复，PR准备提出

[GG-li]

1.9已提PR：vllm-project#680

[GG-li]

1.15 修复CI问题 待检视

[GG-li]

1.19提PRhttps://github.com/vllm-project/pull/843

[GG-li]

无需做出修改 即可完成需求

curl http://localhost:8888/v1/chat/completions -H "Content-Type: application/json" -d '{"model": "/home/models/Qwen/Qwen3-Omni-30B-A3B-Instruct", "messages": [{"role": "user", "content": "Describe vLLM in brief."}], "modalities": ["text", "audio"]}' > /home/lsh-omni/aaa.log

[zengchuang-hw]

PR已合入，问题回归

[yenuo26]

回归通过
携带 modalities=["audio"]调用请求，请求仅返回audio内容
ChatCompletion(id='chatcmpl-982669a5b2ae3879', choices=[Choice(finish_reason='stop', index=0, logprobs=None, message=ChatCompletionMessage(content=None, refusal=None, role='assistant', annotations=None, audio=ChatCompletionAudio(id='audio-b1f7ddb4b8094f71', data='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