Extending the range of black versions that are supported

[tvetterli-fn]

Hello,

Thanks for the awesome project, love using it in my notebook work :)

We are currently trying to use blackcell magic with a project using:

• black == 22.3.0
• click == 8.1.3

We need to use the latest version of black because black 21.9b0 is incompatible with latest click.

This PR is to relax the black dependencies for the blackcellmagic package so that we can install it alongside our other dependenceis.

Tested by loading blackcellmagic in a notebook and it works with black 22.3

[bnaul]

black is up to 22.6.0 now, @csurfer what do you think about relaxing the version bounds?