Revert `np.int_` and `np.uint` changes
Hi!
In the last NumPy community meeting a decision was made that `np.int_` and `np.uint` should stay and they won't be a direct mapping to `np.long` and `np.ulong` (https://github.com/numpy/numpy/pull/24794#issuecomment-1760722889).

This PR reverts my two commits that were added.
Sorry for confusion! It turns out that it's fine to replace `np.long` with `np.int_` (and `np.int_` will stay), so no need to revert these changes - I will double-check the changes but this PR won't be merged. Superseded by https://github.com/pandas-dev/pandas/pull/55540. 