Bump gulp-sass from 5.1.0 to 6.0.0 in /csunplugged

Bumps [gulp-sass](https://github.com/dlmanning/gulp-sass) from 5.1.0 to 6.0.0.
- [Release notes](https://github.com/dlmanning/gulp-sass/releases)
- [Changelog](https://github.com/dlmanning/gulp-sass/blob/master/CHANGELOG.md)
- [Commits](dlmanning/gulp-sass@v5.1.0...v6.0.0)

---
updated-dependencies:
- dependency-name: gulp-sass
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

csunplugged/package.json

@@ -22,7 +22,7 @@
         "gulp-if": "3.0.0",
         "gulp-imagemin": "9.1.0",
         "gulp-postcss": "10.0.0",
-        "gulp-sass": "5.1.0",
+        "gulp-sass": "6.0.0",
         "gulp-sourcemaps": "3.0.0",
         "gulp-tap": "2.0.0",
         "gulp-terser": "2.1.0",