Breaks on Python 3.12

[JoeHCQ1]

Trying to install it while using Python 12. I end up getting a bunch of C2039 compiler errors while building greenlet. From this https://github.com/python-greenlet/greenlet/issues/363, looks like an update is available that fixes this. However, is not a direct dependency of this package. It looks to me, like this is brought in by the docopt dependency. docopt doesn't appear to be an actively maintained package.