MNT: re-configuring ruff for maximal impact and minimal maintenance burden #20519

This topic has been repeatedly touched for a couple years; the status quo is that we enable all linting rules, and only selectively disable the ones we deem unenforceable or inappropriate. As a result, any newly stabilized rule (which come up every couple months with ruff's feature releases) warrant churn and possibly discussion I think a majority¹ would rather skip.

I propose we re-configure ruff towards an opt-in strategy (instead of the current opt-out strat).
Specifically, I propose that we opt into correctness-oriented rules but leave out purely stylistic ones.
I expect this selection will soon become much easier to perform with the categorisation being developed (and available as a preview feature) within the 0.16.x series:
https://docs.astral.sh/ruff/linter/#rule-categories

We could start by trying it out now, and consider using it before it's stabilized if we don't encounter any issue with it, or we could wait for this system to be stabilized (supposedly with ruff 0.17.0).