ENH: Allow Series.apply to accept list-like and dict-like
- [x] closes #39140
- [x] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [x] whatsnew entry

I only added the Series.apply list/dict-like addition to the whatsnew. For both Series and DataFrame .agg, this PR also enables passing a Series as a dict-like, but other dict-likes already work. It didn't seem notable to add this to the whatsnew.
if my comment works ok, otherwise lgtm. merge either way. Thanks @jreback - your comment did work, but I found that just removing the keyword `axis` also works. thanks @rhshadrach 