Bump @stoplight/spectral-cli from 6.6.0 to 6.8.0

Bumps [@stoplight/spectral-cli](https://github.com/stoplightio/spectral) from 6.6.0 to 6.8.0.
- [Release notes](https://github.com/stoplightio/spectral/releases)
- [Changelog](https://github.com/stoplightio/spectral/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/stoplightio/spectral/compare/@stoplight/spectral-cli-v6.6.0...v6.8.0)

---
updated-dependencies:
- dependency-name: "@stoplight/spectral-cli"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]