`pip install -r requirements-dev.txt` takes an extraordinarily long time

[nathan-weinberg]

Something about langchain (coming from the ragas requirement) is trying to install a million different versions of the package

To reproduce, create a Python 3.11 virtual environment via python3.11 -m venv venv and do pip install -r requirements-dev.txt

[booxter]

Use -c constraints-dev.txt to help the pip resolver with resolution.