[CLN] Un-xfail now-passing tests
Some of these were fixed in #21861, others sometime earlier this year, unclear.

Removes un unused util `docstring_wrapper`, closing #19676

- [x] closes #19676
- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`


Closing for now to clear the queue.