Non-Deep copy for Categorical?
Categorical.copy passes `values=self._codes.copy()`, and doesn't have a `deep=False` kwarg (which the base ExtensionArray does).  This is causing trouble in #26954.  Is this intentional @TomAugspurger?

Pandas-internal EAs with `copy` behavior not respecting `deep` kwarg:
- [ ] Categorical (no kwarg at all)
- [ ] DatetimeLike (ignores kwarg)
- [ ] PandasArray

IntegerArray, IntervalArray, and SparseArray look correct.
