Add support for numpy 2.0+

[bpleshakov]

🚀 Feature

Actually, the title. Right now captum has a constraint numpy<2.0 for no apparent reason

Motivation

I want to use captum with modern versions of numpy in the same env.

[aywi]

Related pull request: #1580
Captum itself has no problem supporting NumPy 2.x, as was the case with Captum v0.7.0. The major problem is that the current version of Captum still supports PyTorch <2.3.0, which is incompatible with NumPy 2.x and causes the test builds to fail.

[aobo-y]

@aywi @bpleshakov thank you for the suggestion and investigating the reason.
we will consider stop supporting legacy deps in our next release

cc @craymichael @vivekmig