Python 3.11

[kaapstorm]

@bradleyayers @dag I am not sure who to notify on this pull request.

Recently I recalled Attest, the one Python testing library that does testing right, by using idiomatic Python, and without magical fixtures. I last checked on it a while ago, and it looked dormant, and I sadly went back to pytest. But this weekend I thought I'd ask Claude to help me to migrate it to Python 3.11. This is the result.

There is more to do, but I thought I'd pause, open a pull request, and use it as an opportunity to ask you some questions:

1. Are either of you the right people to be asking these questions? Should someone else be notified of this pull request? Or is Attest dead, and I should quietly walk away?
2. Is this pull request welcome?
3. Do you want more detail in the commit messages?
4. attest/deprecated.py imports lxml, but it is not listed as a dependency. Should it be?
5. I started linting, and then decided to hold off on that for now. Do you have opinions on what to change and what to leave?
6. And of course, what in this pull request do you think I should change?

[dag]

I don't think anyone is actively working on Attest anymore. I'd be happy to add you to the GitHub and PyPI if you want to work on it?

[kaapstorm]

That would be cool! If my email address would help, it's "norman at kaapstorm dot com".

[dag]

That would be cool! If my email address would help, it's "norman at kaapstorm dot com".

I've added you to the GitHub, but (as you can see above) I'm currently locked out of PyPI and they say "There may be a delay of a week or more between responses for these issues."