Pytest should display PEP-678 exception notes in long, auto, and short traceback print modes

[Zac-HD]

Pytest has six traceback print modes - auto (the default), long, short, no, line, or native - which can be selected with the --tb= command-line option. Currently, PEP-678 notes are only displayed in native mode, which is likely to become a problem as various libraries add notes (e.g. here). Ideally, we could get support out to most pytest users before Python 3.11 final, so that everything just works.

I think that we probably don't want to display notes in line or no modes, but the others should.

[Zac-HD]

It looks like this is better addressed in the exceptiongroup backport, by patching traceback.TracebackException.format_exception_only()