Bump postcss-loader from 7.2.4 to 7.3.0

Bumps [postcss-loader](https://github.com/webpack-contrib/postcss-loader) from 7.2.4 to 7.3.0.
- [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/v7.2.4...v7.3.0)

---
updated-dependencies:
- dependency-name: postcss-loader
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

package.json

@@ -51,7 +51,7 @@
     "mini-css-extract-plugin": "^2.7.5",
     "node-sass": "^8.0.0",
     "postcss": "^8.4.23",
-    "postcss-loader": "^7.2.4",
+    "postcss-loader": "^7.3.0",
     "postcss-scss": "^4.0.6",
     "sass": "^1.62.0",
     "sass-loader": "^13.2.2",