feat: use commit-check-action to check PR title

[shenxianpeng]

I've been maintaining commit-check for about 4 years now. It's mature enough to use the commit-check-action in their CI.

This PR eats my own dog food :)

What changed

Before: The check-pr-title job in pre-commit.yml installed a full Rust toolchain (rustup, cargo-binstall, committed) just to validate one PR title.

After: Uses commit-check-action with pr-title: true. The action discovers .github/commit-check.toml automatically — no extra setup needed.

Also added commit-check.toml to mirror the rules we had in committed.toml.

Diff

• Rust toolchain setup gone (removed ~15 lines)
• Two checkouts → one checkout (action auto-discovers config from .github/)
• cspell spell check kept as a separate step
• +27 -30 net

Not in this PR

• The old .github/committed.toml is kept for now (can clean up later)
• Other repos in the org that call this workflow may need their own commit-check.toml or use inherit_from — that's a follow-up

[shenxianpeng]

This PR is not ready and still needs to think about how to make it work as expected.

I will come back when I have time.

[2bndy5]

Before: The check-pr-title job in pre-commit.yml installed a full Rust toolchain (rustup, cargo-binstall, committed)

We could have also just used pipx run committed ...; this was an oversight on my part.

---

My only main concern is adhering to conventional commits standards. This is because generating a changelog or release notes (via git-clff in cpp-linter-rs project) requires using a conventional commit title.

So, if

[commit]
# https://www.conventionalcommits.org
conventional_commits = true

means it enforces type(scope): title (where (scope) is optional), then I'm ok with this.