this is the final part of
https://github.com/certbot/certbot/issues/10195. this fixes
https://github.com/certbot/certbot/issues/10195
the changes in the first commit were done automatically with the
command:
```
ruff check --fix --extend-select UP006 --unsafe-fixes
```
the second commit configures ruff to check for this to avoid regressions
thanks for bearing with me thru these somewhat large automatically
generated PRs ohemorange 🙏
Alternative implementation for #7908.
In this PR:
- set up ruff in CI (add to `tox.ini`, mark dep in `certbot/setup.py`)
- add a `ruff.toml` that ignores particularly annoying errors. I think
line length isn't actually necessary to set with this workflow since
we're not checking it but putting it there for future usage.
- either fix or ignore the rest of the errors that come with the default
linting configuration. fixed errors are mostly unused variables. ignored
are usually where we're doing weird import things for a specific reason.