kendra_retriever_samples/requirement.txt needs update

[rovitini]

Existing requirements.txt version refers to a wrong langchain version

• langchain==0.0.219 >>> does not exist
  +langchain==0.0.21
  boto3>=1.26.159
  openai
  anthropic
  streamlit

---

after updating langchain to 0.0.21, prompt suggest to use the pip 2020 feature resolver:
pip install -r requirements.txt --use-feature=2020-resolver

Resulted in :
Successfully uninstalled pydantic-2.0.3
Successfully installed pydantic-1.10.12

[rovitini]

this error happened, when using cloud9.

[athewsey]

Hi, I can confirm langchain==0.0.219 does exist and installs fine for me. I think the most likely cause of this is you need to upgrade your Python version? Per the link, v0.0.219 requires Python >=3.8.1, <4.0

I probably wouldn't recommend downloading to such an old version as 0.0.21 - the library has changed quite a bit since then.

[MithilShah]

Upgraded to langchain 0.0.263