__repr__ not supported in numba >0.56

[knaaptime]

with recent versions of numba, instantiating a class will raise Method '__repr__' is not supported.. I think this is because __repr__ is now set internally by jitclass, and thus we can't set it manually. If I delete that repr definition, everything works (though the str representation gets wonky).

tl;dr since numba kinda wraps the __repr__ and __str__ now, i think it would probably be fine to just delete those definitions. The new ones coming from jitclass should work fine in most cases, and it seems unlikely folks would've built on the existing versions, so nothing will break if it changes.

The other solution would be to pin numba<0.56, but that seems less than ideal