Add support for OpenAI Responses API and remote MCP servers in LangChain::Assistant class

[vsbriceno]

I currently use the Langchain::Assistant class with an OpenAI model and custom tools, but I would like to extend it by connecting to remote MCP servers. Since the Chat Completions API does not support MCP connections, I’d like to be able to use the OpenAI Responses API within the Assistant class.

[magdalenanario]

any updates on this? Im currently running into the same need.