Liger GPT OSS support

[vaibhavjindal]

🚀 The feature, motivation and pitch

OpenAI released GPT-oss: https://github.com/huggingface/transformers/releases/tag/v4.55.0 https://openai.com/index/introducing-gpt-oss/

Would be great to have it supported in liger-kernel.

Alternatives

No response

Additional context

No response

[Comet0322]

I would like to work on this issue.

[ParagEkbote]

Since #949 has been merged, can this issue be closed?

cc: @Tcc0403