Support Numpy v2

[oscarhiggott]

The recent release of numpy v2 is not yet supported by pymatching.

This should have been fixable simply by updating the pybind11 submodule to v2.12 or later, however this same pyind11 update also results in a Windows fatal exception: access violation for Windows builds of pymatching (#99). It's not yet clear if this is a bug in pymatching or pybind11, but it needs to be fixed to support numpy v2.