[gpt-oss] use vLLM instead of openai types for streaming#25186

hmellor merged 6 commits intovllm-project:mainvllm-project/vllm:mainfrom

qandrew:gpt-oss-streaming-3-wrap-typesqandrew/vllm:gpt-oss-streaming-3-wrap-typesCopy head branch name to clipboard