build(deps-dev): bump sass in /build/frontend-legacy

Bumps [sass](https://github.com/sass/dart-sass) from 1.102.0 to 1.103.1.
- [Release notes](https://github.com/sass/dart-sass/releases)
- [Changelog](https://github.com/sass/dart-sass/blob/main/CHANGELOG.md)
- [Commits](sass/dart-sass@1.102.0...1.103.1)

---
updated-dependencies:
- dependency-name: sass
  dependency-version: 1.103.1
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]