- update to 2.21.0:
* Require new-enough virtualenv to prevent 3.10 breakage
* Respect aliases with `SKIP` for environment install.
* Allow `pre-commit run --files` against unmerged paths.
* Also apply regex warnings to `repo: local` hooks.
* `rust` is now a "first class" language -- supporting `language_version`
* `r` now uses more-reliable binary installation.
* `GIT_ALLOW_PROTOCOL` is now passed through for git operations.
* `GIT_ASKPASS` is now passed through for git operations.
* Remove `toml` dependency by using `cargo add` directly.
* Support `dotnet` hooks which have dotted prefixes.
* ### Fixes
* Properly adjust `--commit-msg-filename` if run from a sub directory.
* Simplify `--intent-to-add` detection by using `git diff`.
* Fix `R.exe` selection on windows.
* Skip default `nuget` source when installing `dotnet` packages.