Add missing setuptools dependency. This should fix JupyterLite issue.

[jmshea]

See jupyterlite/jupyterlite#818

Note that I bumped the minimum Python version to 3.8 because SciPy would not install without that change.

[kolibril13]

Thanks!

[kolibril13]

Hi @jmshea !
Seems like the setuptools approach was causing some problems with GoogleColab:
#47
I saw that you got an alternativ solution in jupyterlite/jupyterlite#818 (comment), the question:
Would you have some free minutes to implement the importlib.resources instead of setuptools approach here as well?
That would be an amazing contribution!
I removed the setuptools dependency already.

[jmshea]

Sure, I can do it