Unpins sqlAlchemy
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/datasets/pr_5595). All of your documentation changes will be reflected on that endpoint. It looks like this issue hasn't been fixed yet, so let's wait a bit more. @lazarust thanks for your work, but unfortunately we cannot merge it.

See my comment in: https://github.com/huggingface/datasets/issues/5477#issuecomment-1495512688

The fix was released yesterday (2023-04-03) only in `pandas-2.0.0`:
- https://github.com/pandas-dev/pandas/releases/tag/v2.0.0

but it will not be back-ported to `pandas-1`:
- https://github.com/pandas-dev/pandas/pull/48576#issuecomment-1466467159

Also note that `pandas-2.0.0` dropped support for Python 3.7:
- https://github.com/pandas-dev/pandas/issues/41678
- https://github.com/pandas-dev/pandas/pull/41989

Therefore, we cannot unpin `sqlalchemy` until we drop support for Python 3.7 (these Python users cannot use `pandas-2`). See our latest CI checks below:
- "CI / test" fails because it runs on Python 3.7
- "CI / test_py310" succeeds because it runs on Python 3.10 
Closes #5477 