Bump node-sass from 4.14.1 to 9.0.0 in /source

Bumps [node-sass](https://github.com/sass/node-sass) from 4.14.1 to 9.0.0.
- [Release notes](https://github.com/sass/node-sass/releases)
- [Changelog](https://github.com/sass/node-sass/blob/master/CHANGELOG.md)
- [Commits](sass/node-sass@v4.14.1...v9.0.0)

---
updated-dependencies:
- dependency-name: node-sass
  dependency-type: direct:development
...

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

source/package.json

@@ -47,7 +47,7 @@
     "imagemin-mozjpeg": "9.0.0",
     "lint-staged": "10.2.11",
     "merge-stream": "2.0.0",
-    "node-sass": "4.14.1",
+    "node-sass": "9.0.0",
     "postcss-reporter": "6.0.1",
     "postcss-scss": "2.1.1",
     "stylelint": "13.6.1",