DEPR: change DataFrame.append default sort kwarg
xref #20613

AFAICT this doesn't break any tests, was this supposed to have been changed along with the default in `concat` #29786 ?
> xref #20613
> 
> AFAICT this doesn't break any tests, was this supposed to have been changed along with the default in `concat` #29786 ?

IIRC this was changed *already* for 1.0, so *may* need to delay this > IIRC this was changed already for 1.0, so may need to delay this

The last time the relevant part of the docstring was changed was in #20613, the same PR that deprecated the old pd.concat default behavior. thanks @jbrockmendel must have been thinking about something else