remove Python<3.10 restriction

[cjdoris]

We restrict to Python<3.10 in PythonCallDeps.toml because conda appears to have issues with two-digit minor version numbers.

[PallHaraldsson]

Seeing this issue, I thought I should inform you of this Conda-compatible package I saw the other day: https://github.com/cjdoris/MicroMamba.jl

Then I realized it's your work... but at least it loads twice as fast, so you might want to substitute (Conda needs to be fixed also, or both if not already handling). Also I think you can load less-used packages conditionally,

[cjdoris]

Yep I'm working on some packages to factor out the dependency handling part of PythonCall.

[cjdoris]

Fixed now we use MicroMamba+CondaPkg.