.github: Bump actions/checkout from 4.2.2 to 6.0.1

.github: Bump actions/checkout from 4.2.2 to 6.0.1

Bumps [actions/checkout](https://github.com/actions/checkout) from 4.2.2 to 6.0.1.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/11bd71901bbe5b1630ceea73d27597364c9af683...8e8c483db84b4bee98b60c0593521ed34d9990e8)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>