No longer builds on Python 3.9 + Numpy 1.26.3 + Cython 3.0.6

[aluo-x]

Not sure when exactly this started happening, but currently I can no longer build this package on the configuration listed above.

Fails at compiling openctm, and fails with CTMenum which it tell me is not a type identifier.

[aluo-x]

Ah, nvm I see that Cython 3.x is not supported. I'll leave this issue for comment, but will close it in 5 days otherwise.