Version in setup.cfg

[aburrell]

Is your feature request related to a problem? Please describe.
It may be possible to remove the version number in setup.cfg file.

Describe the solution you'd like
It would be easier to have to update the version number in less places

Describe alternatives you've considered
It may still be necessary for some implementations? Should be ok with mininmum Python version of 3.9 (according to @jklenzing).