Update requirements for numpy 2

[hyanwong]

This won't work until scikit-allel is numpy 2.0 compatible. See cggh/scikit-allel#415

Also note that the tszip docs are linked to the latest not stable version. See tskit-dev/tszip#67 (comment)

[hyanwong]

There's also something weird going on with the R interface here, although it's all compiling locally for me. Something in the R setup could possibly do with changing. This could require some fiddling.

[benjeffery]

I've made a start on the scikit-allel, but one of the tests is failing and I don't get why: cggh/scikit-allel#416

[hyanwong]

I pinned to the latest non v2 version of numpy, and it all seems to work, so I think we can just merge this and unpin numpy when scikit-allel is updated.

[jeromekelleher]

SGTM