hghave: add py312 and py313
While not required in the core test suite in the moment, these could be useful
in the future or for extensions. For example, Python 3.12 removed distutils and
it might make sense to differentiate based on that.
[workspace]
members = ["hg-core", "hg-cpython", "rhg"]
exclude = ["chg", "hgcli"]
resolver = "2"