Running iotest linters from check-python-* CI jobs

[John Snow]

Hi Kevin:

At one point I had the idea to augment the Python linter CI jobs to also 
run the iotest linters. I thought it would be convenient to ensure that 
while I changed around the QMP and Machine packages that I didn't 
introduce regressions in iotest 297 either.

I sent an RFC, got feedback from Vladimir (Who seemed broadly in favor 
of the idea), and then wrote a v2 that I never sent.

RFC: Message-Id: <20210604163907.1511224-1-jsnow@redhat.com>

mreitz stated (on IRC) in no uncertain terms they were not happy with 
the idea of 297 becoming gating CI, so I held off on pursuing the idea. 
I wanted to reach out and see if you had feelings on the matter, or if I 
should indeed just shelve it entirely.

--js