Bump postcss-loader from 4.2.0 to 5.0.0

Bumps [postcss-loader](https://github.com/webpack-contrib/postcss-loader) from 4.2.0 to 5.0.0.
- [Release notes](https://github.com/webpack-contrib/postcss-loader/releases)
- [Changelog](https://github.com/webpack-contrib/postcss-loader/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack-contrib/postcss-loader/compare/v4.2.0...v5.0.0)

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

package.json

@@ -51,7 +51,7 @@
     "mini-css-extract-plugin": "^1.3.5",
     "node-sass": "^5.0.0",
     "postcss": "^8.2.4",
-    "postcss-loader": "^4.2.0",
+    "postcss-loader": "^5.0.0",
     "sass": "^1.32.6",
     "sass-loader": "^10.1.1",
     "style-loader": "^2.0.0",