Update langchain pin to 0.0.331

[rmitsch]

Description

Update langchain pin to 0.0.331.

Corresponding documentation PR

-

Types of change

Chore.

Checklist

• I confirm that I have the right to submit this contribution under the project's MIT license.
• I ran all tests in tests and usage_examples/tests, and all new and existing tests passed. This includes
  • all external tests (i. e. pytest ran with --external)
  • all tests requiring a GPU (i. e. pytest ran with --gpu)
• My changes don't require a change to the documentation, or if they do, I've added all required information.

[rmitsch]

Note: run external tests before merging once OpenAI API works again.

[svlandeg]

Feel free to merge once we can get the tests to run and they go green!

[rmitsch]

For posterity: the openai pin is necessary due to a conflict of langchain with openai > 0.28.1. See langchain-ai/langchain#12967.