Avoid upgrading LangChain beyond version 0.0.33 (until further notice)

[mayooear]

A lot of the issues faced whilst using this repo are caused by upgrading above the LangChain 0.0.33 version used.

There are a few bugs in the latest LangChain version that will cause your ingestion script to fail. Contributors including myself are working hard to fix and resolve these bugs.

In the meantime, stick to the exact package versioning used in this repo.

The same applies to pinecone.