MNT: upgrade to py3 syntax, once over with ruff

[tangkong]

This is a doozy, mostly throwing this up here to examine the diff and see what the changes might be.

None of these have tests, so this could all break catastrophically 🤷

partially addresses #11 In response to https://jira.slac.stanford.edu/browse/ECS-5719

[ZLLentz]

Magic incantation for running this is:

• get your python env set up e.g. source pcds_conda
• cd OUT of the directory with cd ..
• python -m IocManager.IocManager --hutch rix, to check rix for example

[tangkong]

It's also necessary to setup the same IOCmanager env https://github.com/pcdshub/engineering_tools/blob/master/scripts/iocmanager

If I don't do this all the statuses show up as "ERROR"