Support NumPy versions >= 2.0
Since version 1.25, libraries built with newer NumPy versions will be compatible with the oldest supported NumPy version, e.g., for Python 3.9, this is NumPy version 1.19.
To support NumPy version >= 2.0, the build must not use NumPy versions 1.X any more.
Therefore, start using the newest NumPy version available for Python >= 3.9 and only keep using the oldest supported NumPy version for older Python versions.