Hotfix/dependency update

[mfakaehler]

Until issue #1245 and PR #1236 are resolved, I propose to update the dependencies in the README.md and pyproject.toml files to make the current incompatability to jupyterlab 4 explicit.
Please, feel free to make any adjustments.
If you feel it is unnecessary to document this (probably) intermediate issue of incompatibility, please feel free to deny the pull request.

[welcome]

Thanks for submitting your first pull request! You are awesome! 🤗

If you haven't done so already, check out Jupyter's Code of Conduct. Also, please make sure you followed the pull request template, as this will help us review your contribution more quickly.

You can meet the other Jovyans by joining our Discourse forum. There is also a intro thread there where you can stop by and say Hi! 👋

Welcome to the Jupyter community! 🎉

[github-actions]

👈 Launch a binder notebook on branch mfakaehler/jupyterlab-git/hotfix/dependency_update

[fcollonval]

Thanks @mfakaehler

One change is unneeded but the README change looks good.

[fcollonval]

That one is not needed because it is use only to build the package and Python requirement >=3.0.0rc13,==3.* is equivalent to >=3.0.0rc13 and ==3.* (see PEP)

Suggested change

	requires = ["jupyter_packaging~=0.7.9", "jupyterlab>=3.0.0rc13,==3.*,<4", "packaging", "setuptools>=40.8.0", "wheel"]
	requires = ["jupyter_packaging~=0.7.9", "jupyterlab>=3.0.0rc13,==3.*", "packaging", "setuptools>=40.8.0", "wheel"]

[mfakaehler]

Maybe one should also mark the dependency problem in the conda-forge feedstock?

[welcome]

Congrats on your first merged pull request in this project! 🎉

Thank you for contributing, we are very proud of you! ❤️