Remove numpy dependency after upgrading to pytorch 2.x

[dxoigmn]

          It looks like the newer PyTorch 2.0 has resolved the issue: https://github.com/pytorch/pytorch/pull/91517#issuecomment-1477998981

Could you add a note in the comment? I think we will upgrade to PyTorch 2.0 soon after torchmetrics fixes mAP.

Originally posted by @mzweilin in #144 (comment)