CI improvements & speedups

[stenczelt]

problems

The CI is very slow:

• pre-commit takes 4m (no speedup from caching)
• unit-tests take over 20 minutes

Looking at the test suite, there are not all "unittests" per se, but include a lot of integration/e2e etc. test as well. This is very good, however confusing and more difficult for local development.

proposed changes

1. speed up the pre-commit CI job
2. categorise tests and separate fast and slow ones

[CompRhys]

+1

ruff would cut most of the time from linting. Swapping to using prek rather than pre-commit would save time for the pre-commit action more generally.

using uv pip as opposed to pip would save around 2 minutes out of 20 on unit-tests.

These are all "free" wins now that python 3.8 support has finally been dropped!

#534, #537

[CompRhys]

I made #1378 to swap over to use some faster tooling tools. Pylint is still a reasonable bottleneck on linting in CI. pyright, basedpyright, or ty are all faster alternatives.

basedpyright found "1777 errors, 11628 warnings, 0 notes", whilst ty "Found 1238 diagnostics" that need resolving, so moving over to any of these tools is a heavier lift.

[CompRhys]

Okay have fixed/resolved all the pylint errors at least such that the CI action passes. I did make some changes to the inlined pyg code so silence the linter but that code has been untouched so long that I imagine it has diverged from prod anyway and so shouldn't be treated as a vitrified asset.