Build(deps-dev): Bump autoprefixer from 10.4.19 to 10.4.20 in /frontend

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 10.4.19 to 10.4.20.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/main/CHANGELOG.md)
- [Commits](postcss/autoprefixer@10.4.19...10.4.20)

---
updated-dependencies:
- dependency-name: autoprefixer
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

frontend/package.json

@@ -21,7 +21,7 @@
     "@types/jest": "^27.5.0",
     "@types/react": "^18.3.3",
     "@types/react-dom": "^18.3.0",
-    "autoprefixer": "^10.4.19",
+    "autoprefixer": "^10.4.20",
     "clean-webpack-plugin": "^4.0.0",
     "copy-webpack-plugin": "^12.0.2",
     "css-loader": "^7.1.2",