Bump @csstools/postcss-sass from 5.0.1 to 5.1.1

Bumps [@csstools/postcss-sass](https://github.com/jonathantneal/postcss-sass) from 5.0.1 to 5.1.1.
- [Release notes](https://github.com/jonathantneal/postcss-sass/releases)
- [Changelog](https://github.com/csstools/postcss-sass/blob/main/CHANGELOG.md)
- [Commits](https://github.com/jonathantneal/postcss-sass/commits)

---
updated-dependencies:
- dependency-name: "@csstools/postcss-sass"
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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