Upgrade to `python-constraint2`

[redeboer]

Since python-constraint2 is not in beta anymore, it might be that the problems in #293 are not an issue anymore. Also note that binaries are provided for 3.14 as well since v2.5.0.

Note

uv warns that

warning: python-constraint==1.4.0 uses a legacy source distribution format ('.tar.bz2') that is not compliant with PEP 625. A future version of uv will reject this source distribution. Consider upgradeing to a new version of python-constraint