Release pre-commit v4.0.0 · pre-commit/pre-commit

Improve pre-commit migrate-config to handle more yaml formats.
- #3301 PR by @asottile.
Handle stages deprecation in pre-commit migrate-config.
- #3302 PR by @asottile.
- #2732 issue by @asottile.
Upgrade ruby-build.
- #3199 PR by @thisguycodes.
Add "sensible regex" warnings to repo: meta.
- #3311 PR by @asottile.
Add warnings for deprecated stages (commit -> pre-commit, push ->
pre-push, merge-commit -> pre-merge-commit).
- #3312 PR by @asottile.
- #3313 PR by @asottile.
- #3315 PR by @asottile.
- #2732 issue by @asottile.

language: python_venv has been removed -- use language: python instead.
- #3320 PR by @asottile.
- #2734 issue by @asottile.