Bump oas-resolver from 2.2.4 to 2.2.8

Bumps [oas-resolver](https://github.com/Mermade/oas-kit) from 2.2.4 to 2.2.8.
- [Release notes](https://github.com/Mermade/oas-kit/releases)
- [Changelog](https://github.com/Mermade/oas-kit/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Mermade/oas-kit/compare/oas-resolver@2.2.4...oas-resolver@2.2.8)

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