Bump the regular-updates group across 1 directory with 3 updates

Bumps the regular-updates group with 3 updates in the / directory: [marked-highlight](https://github.com/markedjs/marked-highlight), [postcss](https://github.com/postcss/postcss) and [stylelint-scss](https://github.com/stylelint-scss/stylelint-scss).


Updates `marked-highlight` from 2.2.0 to 2.2.1
- [Release notes](https://github.com/markedjs/marked-highlight/releases)
- [Changelog](https://github.com/markedjs/marked-highlight/blob/main/release.config.cjs)
- [Commits](markedjs/marked-highlight@v2.2.0...v2.2.1)

Updates `postcss` from 8.4.47 to 8.4.49
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@8.4.47...8.4.49)

Updates `stylelint-scss` from 6.8.1 to 6.9.0
- [Release notes](https://github.com/stylelint-scss/stylelint-scss/releases)
- [Changelog](https://github.com/stylelint-scss/stylelint-scss/blob/master/CHANGELOG.md)
- [Commits](stylelint-scss/stylelint-scss@v6.8.1...v6.9.0)

---
updated-dependencies:
- dependency-name: marked-highlight
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: regular-updates
- dependency-name: postcss
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: regular-updates
- dependency-name: stylelint-scss
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: regular-updates
...

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