DOC: RT03 fix for various DataFrameGroupBy and SeriesGroupBy methods
- [x] xref https://github.com/pandas-dev/pandas/issues/57416
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

/preview Website preview of this PR available at: https://pandas.pydata.org/preview/pandas-dev/pandas/57862/ @quangngd we changed how we specify the pending errors in `code_checks.sh` and you'll have to resolve the conflicts. Sorry for the inconvenience. @datapythonista resolved Thanks @quangngd 