Bump rakutentech/laravel-request-docs from 2.25 to 2.28

Bumps [rakutentech/laravel-request-docs](https://github.com/rakutentech/laravel-request-docs) from 2.25 to 2.28.
- [Release notes](https://github.com/rakutentech/laravel-request-docs/releases)
- [Commits](rakutentech/laravel-request-docs@v2.25...v2.28)

---
updated-dependencies:
- dependency-name: rakutentech/laravel-request-docs
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>