Sorted flag is incorrectly preserved through arithmetic overflow

[orlp]

We currently preserve sorted flags when adding a constant, this is incorrect when overflow occurs.

>>> s = pl.Series([0, 200], dtype=pl.UInt8).sort()
>>> s
shape: (2,)
Series: '' [u8]
[
        0
        200
]
>>> s + 200
shape: (2,)
Series: '' [u8]
[
        200
        144
]
>>> (s + 200).is_sorted()
True

[ritchie46]

I think integer arithmetic should not maintain sorted flag. Can you fix this one?