• closes #xxxx
• tests added / passed
• passes black pandas
• passes git diff upstream/master -u -- "*.py" | flake8 --diff
• whatsnew entry

Related to #27977.

output of python scripts/validate_docstrings.py pandas.DataFrame.select_dtypes:

################################################################################
################################## Validation ##################################
################################################################################

1 Errors found:
        No extended summary found

Notes:
It seems like passing int to the parameter do not include/exclude all integer dtypes. But, passing integer would do otherwise. I think it is related to this issue #29394. It would be more convenient if passing int as an input would match the result with passing integer.