TODO: Remove workaround in boolean_masks_to_categorical_integers function

[NJManganelli]

This is a draft as it hits a still-extant limitation in awkward which prevents actually removing this TODO for now:
scikit-hep/awkward#3312 (comment)

@ikrommyd tested changing the prototype array's dtype to > int8, which resolves the immediate error. Given the name and what it seems to do, it's unclear to me if there should be a try-except logic that starts with int8 and swaps when it reaches overflow, or if this needs some different approach, or if just brute-force swapping to int64 is sufficient.

If and when such an extension is added to awkward and that becomes the minimal version for coffea, this can be further developed (irregular_mask_sequel will need to be validated as having identical contents to the irregular_mask, at which point the slice logic can be deprecated and removed)