Drop Python v3.8 support

[robmoss2k]

isort recently dropped support for Python v3.8. FawltyDeps' dependency on isort="^5.10" breaks projects that use isort="^6.0.0". As Python v3.8 is no longer supported, and according to the Boundaries section of CodeDesign, support should be dropped and the isort requirement should be updated to >=5.10.

Note that the only breaking change in isort 6.0.0 is dropping Python v3.8 support.

[robmoss2k]

Fixes #472. Note that the required Python v3.8 checks will fail until they are updated to remove support for Python v3.8.

[jherland]

Thanks again for the work put into this PR. We've come around to the idea of dropping Python v3.8 support, and I hope to get this PR merged soon. We might want to make another, smaller release before we drop v3.8 support, but I'll get back to that if and when it happens.

A couple of initial observations before I look closer at this PR:

The second commit that you added earlier today ("Update dependencies") unfortunately rewrites the entire pyproject.toml file (did you use some kind of auto-formatter?). For one, it loses all the authors except one, and it's also hard to see what - if any - intentional changes are there in addition to the reformatting. Please drop or redo that commit.

Also, please rebase on current main to fix the conflict mentioned by GitHub here.

[robmoss2k]

That second commit shouldn't have happened - I'll back that one out, sorry. I have a tool that upgrades the pyproject.toml file to get rid of the deprecated fields (mainly the tool.poetry section) but it's completely specific to my setup.

[robmoss2k]

I made the n00b mistake of forgetting to create a branch before creating a PR. I reverted that dependencies commit and rebased it against upstream main. Closing this one in favour of #474.