update some CI versions, move docs-building to a script

[jameslamb]

Contributes to #115

This PR has some miscellaneous small CI things that I noticed while working on adding conda builds in #129. Pulling them into a separate PR to make the diff for that PR smaller.

• adding a Python 3.12 entry to dependencies.yaml
• updating all pre-commit hooks (via pre-commit autoupdate)
• moving docs-building code out of CI configs and into a script
  • (this will become more important in #129 when that logic becomes a bit more involved)

Notes for Reviewers

See comments on the diff for reasoning behind other specific changes.

[jameslamb]

I'm still not quite sold on the idea of pre-commit hook, feels like an elaborate effort to have yet another dependency manager for a simple task

Thanks for this. I felt this way for a long time... working on RAPIDS is the first time I've ever really used pre-commit.

Since I've gotten used to it on RAPIDS repos, I've found it convenient and powerful, relative to every repo having its own slightly different shell scripts or Makefile targets.

For what it's worth, I don't actually use the git functionality at all... I never pre-commit install to make it run as a git hook. I just use this tool to run all static analysis and autoformatting over all files, like pre-commit run --all-files.