Lint tests

[JPEWdev]

Adds lint tests to the test suite so that I stop forgetting to run them

[bact]

The test failed because there is no black installed.

We could put it in the dev group in [project.optional-dependencies] in project.toml

[github-actions]

Coverage report

This PR does not seem to contain any modification to coverable code.

[bact]

Black now passed on Python 3.10-3.14 but failed on 3.8 and 3.9.

The root cause is multiline_string_handling style that was in "preview" stage (disabled by default; can't be enabled alone, has to enable the whole unstable style) before got upgrade to "stable" (can't be disabled) in 2026.1.0 release.

See Black's PR: https://github.com/psf/black/pull/4892/changes#diff-d975bf659606195d2165918f93e1cf680ef68ea3c9cab994f033705fea8238b2R18 and issue psf/black#256

The easiest fix is to drop Python 3.8 and 3.9 from test, and use Black >= 26.1.0.

Or we can try to reformat the code to make it stable across all Black versions.

[bact]

Should we drop Python 3.8 and 3.9 from tests?

[bact]

Should we drop Python 3.8 and 3.9 from tests?

Python 3.8 dropped by #115. Python 3.9 still fails.