build(deps-dev): bump find-unused-sass-variables (#777)

Bumps [find-unused-sass-variables](https://github.com/XhmikosR/find-unused-sass-variables) from 2.0.0 to 3.0.0.
- [Release notes](https://github.com/XhmikosR/find-unused-sass-variables/releases)
- [Commits](https://github.com/XhmikosR/find-unused-sass-variables/compare/v2.0.0...v3.0.0)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

amundsen_application/static/package.json

@@ -92,7 +92,7 @@
     "eslint-plugin-prettier": "^3.1.4",
     "eslint-plugin-react": "^7.20.5",
     "eslint-plugin-react-hooks": "^4.0.4",
-    "find-unused-sass-variables": "^2.0.0",
+    "find-unused-sass-variables": "^3.0.0",
     "html-webpack-plugin": "^4.5.0",
     "husky": "^4.3.0",
     "jest": "^26.6.0",