Numpy: port dtype and its static instances to HPy

[steve-s]

For this iteration I suggest to restrain from porting the dtype metatype. Porting dtype is currently blocked by metaclass support in HPy #296.

[mattip]

Metatypes are supported. Is this part of the NumPy port?

[fangerer]

I think we can close this issue. Yes, metaclasses are now supported in HPy and yes, we basically already did the migration.
It would be nice if we could open issues in https://github.com/hpyproject/numpy-hpy .

[mattip]

I wonder who the owner is for that fork? Perhaps they could open up issues. Maybe @rlamy?

[rlamy]

@mattip I enabled issues there. AFAICT, every hpyproject owner could have done it.

[mattip]

I am a hpyproject member, so I could neither see who is a maintainer nor change the settings.