CLN: rolling step followups

[mroeschke]

• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.

xref #45765

[jreback]

doc string check failing: https://github.com/pandas-dev/pandas/runs/5371271902?check_suite_focus=true

[jreback]

cc @rtpsw

[rtpsw]

doc string check failing: https://github.com/pandas-dev/pandas/runs/5371271902?check_suite_focus=true

Note that, while trying to reproduce this, I got the following error after pulling main:

$ ./ci/code_checks.sh docstrings
Validate docstrings (GL01, GL02, GL03, GL04, GL05, GL06, GL07, GL09, GL10, SS01, SS02, SS03, SS04, SS05, PR03, PR04, PR05, PR06, PR08, PR09, PR10, EX04, RT01, RT04, RT05, SA02, SA03)
Traceback (most recent call last):
  File "./ci/../scripts/validate_docstrings.py", line 32, in <module>
    from numpydoc.docscrape import get_doc_object
ImportError: cannot import name 'get_doc_object' from 'numpydoc.docscrape' (/mnt/user1/tscontract/venv/lib/python3.8/site-packages/numpydoc/docscrape.py)
Validate docstrings (GL01, GL02, GL03, GL04, GL05, GL06, GL07, GL09, GL10, SS01, SS02, SS03, SS04, SS05, PR03, PR04, PR05, PR06, PR08, PR09, PR10, EX04, RT01, RT04, RT05, SA02, SA03) DONE

I was able to move past this error by changing to numpydoc>=1.2.0 in requirements-dev.txt and pip install -r requirements-dev.txt.