Pin NumPy to be lower than 2.0

[knyazer]

Fixes AttributeError: `np.sctypes` was removed in the NumPy 2.0 release. on newer NumPy versions and poetry installation

Reference Issue

None

What does this PR implement/fix? Explain your changes.

Fixes the

AttributeError: `np.sctypes` was removed in the NumPy 2.0 release. Access dtypes explicitly instead.. Did you mean: 'dtypes'?

in the sklearn extension. (line 53, sklearn/extension.py)

You might say "but nobody has ever experienced this issue!". True. For some reason, pip can figure out that the dependency should be lower than 2.0; I don't how it does it. However, I use poetry as a package manager, and if installing openml via poetry, it uses numpy 2.1 as a dependency, which breaks openml.

How should this PR be tested?

Install poetry. Then:

mkdir test && cd test && poetry init -q && poetry add openml && poetry run python -m openml

This would throw before the changes, but would not after the changes.

Any other comments?

Should be pretty easy to merge.

[PGijsbers]

Did you try yet to install from GitHub? The develop branch should already be numpy 2.0 compatible: #1341

[knyazer]

No, I actually did not :(

Yep, it works on the development version. Annoying that it is not yet on the pypi.

Sorry for the noise, then.