NumPy 2 support
The version requirement in pyproject.toml is ^1.21.2. The caret is SemVer-compatible, so the resulting wheel requires numpy>=1.21.2, <2.0.0.
NumPy 2 has been out for several months now, and it would be good to allow it. AFAICT, there are no compiled extensions here, so it should be relatively easy to allow.