To provide an API to pass the fetch instance for the ChatOllama class

[Albert-Gao]

Checked

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Feature request

For the ChatOpenAI, we can pass the fetch like this:

import { ChatOpenAI } from "@langchain/openai";

new ChatOpenAI({
       configuration: {
              fetch: myFetch
       }
})

I wish I could do the same for the ChatOllama class, currently, it does not support it.

Motivation

Can not do the same for the import { ChatOllama } from "@langchain/community/chat_models/ollama";, would be great if we can have this feature, since we need this for react-native, the default fetch does not support stream, we need to use a different fetch instance to enable fetching with stream. Thanks :)``

Proposal (If applicable)

No response