Bump postcss-scss from 4.0.5 to 4.0.6 (#21814)

Bumps [postcss-scss](https://github.com/postcss/postcss-scss) from 4.0.5 to 4.0.6.
- [Release notes](https://github.com/postcss/postcss-scss/releases)
- [Changelog](https://github.com/postcss/postcss-scss/blob/main/CHANGELOG.md)
- [Commits](https://github.com/postcss/postcss-scss/compare/4.0.5...4.0.6

)

---
updated-dependencies:
- dependency-name: postcss-scss
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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