docs: update Confident AI callback docs

[spike-spiegel-21]

URL

https://python.langchain.com/docs/integrations/callbacks/confident/

Checklist

• I added a very descriptive title to this issue.
• I included a link to the documentation page I am referring to (if applicable).

Issue with current documentation:

The current documentation is deprecated. DeepEvalCallbackHandler is no longer used.

Idea or request for content:

Update the latest docs from here: https://documentation.confident-ai.com/docs/llm-tracing/integrations/langchain

[Jai-Dhiman]

Hi! I'd like to work on updating this documentation.

I've reviewed both the current LangChain docs and the new Confident AI integration guide. The changes needed are substantial:

Key updates needed:

• Replace deprecated DeepEvalCallbackHandler with new CallbackHandler from deepeval.integrations.langchain
• Update installation from langchain langchain-openai langchain-community deepeval langchain-chroma to deepeval langchain langchain-openai
• Replace !deepeval login with deepeval.login("<api-key>")
• Update all code examples to use modern LangChain patterns (init_chat_model vs OpenAI)
• Add new features: trace attributes (name, tags, metadata, thread_id, user_id) and online evaluations

Some Questions:

1. Should I completely replace the content to match the new Confident AI docs structure, or preserve any existing sections?
2. The current docs show metrics like AnswerRelevancy - should these be removed entirely or noted as deprecated?
3. Any specific formatting requirements for LangChain integration docs?

I can have this updated within a few days. Thanks!