Update langchain-retrieval-augmentation notebook for 2025 (#459)

…on of Pinecone

## Problem

Describe the purpose of this change. What problem is being solved and
why?

Old notebook using langchain. 
## Solution

Updated, added new dataset with Pinecone release notes, and following
new Langchain quickstart for RAG located here:
https://python.langchain.com/docs/tutorials/rag/#components




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Author: arjunpatel7