Maintenance for MkDocs 1.5.0

[kamilkrzyskow]

Hi 👋,
MkDocs 1.5.0 adds the theme.custom_dir property for ease of access and deprecates the previous theme._vars and config.user_configs. I updated the script to handle both cases via a simple API check, the assumption currently is that the theme.custom_dir won't be going away so I felt this is a cleaner approach that comparing the mkdocs.__version__.

Also tests will need to be adjusted, since they now rely on the source not changing... the themes change 1.5.0, which in turn will break every test case, because they rely on hashes... 😑I now see that hashes weren't such a good idea, I will try to handle it somehow in the coming days, since I take partial blame in the test design.

If this PR won't be merged before 1.5.0 then the world won't end, people will just have to live with the Deprecation warning for some time.

[wilhelmer]

So this removes the user_configs is never used in MkDocs and will be removed soon deprecation warning when building with MkDocs >1.5. Nice, thanks!

As the warning doesn't indicate which plugin causes this, we should release this to avoid confusion.

@byrnereese Please publish version 0.7.1 on PyPI. Thanks!

[kamilkrzyskow]

Yeah, sorry that I'm taking so long with the simple test refactor, I just can't decide on the best path forward and therefore procrastinate.

I see that the tests passed on GitHub Actions because they don't use the newest MkDocs version, so the test methodology update isn't that urgent.

Thanks for the merge

[byrnereese]

@kamilkrzyskow 0.7.1 released!