[Feat]Support voice clone for omnivoice in online serving & add seed parameter for reproducible (#3668)

Signed-off-by: sphinxkkkbc <binchengkang8@gmail.com>
Co-authored-by: sphinxkkkbc <binchengkang8@gmail.com>

tests/helpers/runtime.py

@@ -1671,7 +1671,7 @@ class OpenAIClientHandler:
         # Qwen3-TTS custom fields, forwarded via extra_body.
         extra_body: dict[str, Any] = {}
         # Keep this list aligned with vllm_omni.entrypoints.openai.protocol.audio params.
-        for key in ("task_type", "ref_text", "ref_audio", "language", "max_new_tokens"):
+        for key in ("task_type", "ref_text", "ref_audio", "language", "max_new_tokens", "seed"):
             if key in request_config:
                 extra_body[key] = request_config[key]