move to python 3.8+

[danieleades]

sphinx 6.0 beta is out, and drops support for python <3.8.
sphinx-needs can follow suit (once the stable release is out)

[danwos]

I would like to close this PR, as it seems to outdated.
Any concerns?

[chrisjsewell]

I would like to close this PR, as it seems to outdated. Any concerns?

@danwos to bump to new versions of sphinx, this would still be required. Python 3.7 is also end-of-life: https://devguide.python.org/versions/

What are your thoughts on bumping python/sphinx versions? Speaking with @ubmarco he suggested that we are less "aggressive" on bumping versions, since some businesses have to deal with older versions of Python?

[ubmarco]

We also have the Compatibility with Sphinx 7.2 PR now.
It contains new version constraints and remarks wrt API incompatibilities.
Support for Sphinx < 7.2 with one version of sphinx-needs will require a lot of code branches to make all Sphinx versions happy.

[chrisjsewell]

superceded by #1056