Bump postcss and css-loader

Bumps [postcss](https://github.com/postcss/postcss) to 8.4.47 and updates ancestor dependency [css-loader](https://github.com/webpack-contrib/css-loader). These dependencies need to be updated together.


Updates `postcss` from 7.0.39 to 8.4.47
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@7.0.39...8.4.47)

Updates `css-loader` from 3.6.0 to 7.1.2
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/css-loader@v3.6.0...v7.1.2)

---
updated-dependencies:
- dependency-name: postcss
  dependency-type: indirect
- dependency-name: css-loader
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

package.json

@@ -47,7 +47,7 @@
     "@fortawesome/free-solid-svg-icons": "^5.1.0-11",
     "@fortawesome/react-fontawesome": "^0.1.8",
     "babel-preset-react": "^6.24.1",
-    "css-loader": "^3.4.0",
+    "css-loader": "^7.1.2",
     "google-map-react": "^1.1.5",
     "history": "^4.10.1",
     "prop-types": "^15.6.1",