update guided decoding param to structured outputs

[jiqing-feng]

The latest vllm changed the guided_decoding to structured_outputs in this PR 22772. We also need to update this parameter in the vllm client and vllm serve.

Hi @qgallouedec . Would you please review this PR? Thanks!

[kashif]

we will need to make sure that we require the version of vllm that supports this feature

[jiqing-feng]

we will need to make sure that we require the version of vllm that supports this feature

Sure, we can wait for the vllm release and then update the vllm version in setup in this PR.

[kashif]

you will need to update this: https://github.com/huggingface/trl/blob/main/setup.cfg#L67

[jiqing-feng]

you will need to update this: https://github.com/huggingface/trl/blob/main/setup.cfg#L67

Yes, exactly. I will update it once vllm 10.3.0 released.

[qgallouedec]

for ref: #4122 will pin vLLM