kramar11

There is no need to call `__post_init__` on copy as the "validation" of the attributes already happened when creating the object. dataclasses don't call `__post_init__` on `copy.copy()` either. While testing...

Thanks for looking into this. But I think msgspec should really be calling `__post_init__` to behave like dataclasses. Also when using `copy.replace` currently `__post_init__` is not called unlike dataclasses does....