Support for Python 3.11?

[rossjjennings]

Currently Enterprise cannot be installed in a Python 3.11 environment (python-requires=">=3.7,<3.11" in setup.py). I don't know how hard it would be to remove this restriction -- is it as simple as bumping the version cap, or is there a real incompatibility? In any case, it's something to think about, especially since 3.11 is now the default Python version on conda-forge.

[vhaasteren]

Solved by #362