Fixes to support numpy>=2.4

[rohanbabbar04]

• Use .item() for singular element.
• Replace np.sum with sum when defining shapes of the stacked operators.
• Remove numpy<=2.3.5 version pinning.

[rohanbabbar04]

I got some time to look at this. Not any major changes, just handling of a single element is where it was breaking.

[mrava87]

Thanks, eveyrhting makes sense to me 😄

@tharittk agree?

[tharittk]

This is great. Thank you @rohanbabbar04 !