Reduce requirements list in setup.cfg

[kwinkunks]

Thanks for continuing to support classic notebooks, and improving the architecture 🙌

Currently the install_requires list is comprehensive:

https://github.com/jupyter/nbclassic/blob/v1.0.0/setup.cfg#L30-L49

But most of these requirements are requirements of jupyter-server, and that is a requirement of notebook-shim so the list could be substantially reduced to:

install_requires:
    ipykernel
    ipython-genutils
    nest-asyncio
    notebook-shim

Personally I think this makes it easier for people to figure out their dependency requirements, but I realize the team may have another viewpoint.

[echarles]

I agree with you @kwinkunks By any chance, would you have appetite to open a PR for this. I would be very happy to review and help you with that.

[RRosio]

#259 has been merged! The changes should be reflected in the next release of NbClassic. I'll go ahead and close this issue. Thanks again!