chore(lint): 🚮 fix linting

[lbillinghamwrk]

Not totally sure we want to do all of this (or indeed any of it).

• make our max line length sensible
  • unlike the 730 chars that we inherited from errbot's pyproject.toml/setup.cfg
• run black over the codebase to autoformat it
• since ruff is the linter defined in the project file: run ruff's auto fix
• manually fix a couple of things that ruff couldn't
• silence the warning for use of the global and apologise for it

[lbillinghamwrk]

@panneeran
even if we don't want to take the other changes in this PR,
i think its still worth having the pyproject line length be sensible, and aligning python versions between here and the Dockerfile

destalinator/Dockerfile

Line 1 in f83e479

FROM python:3.9