Bump postcss and css-loader in /fannie/modules/plugins2.0/MobileLane

Bumps [postcss](https://github.com/postcss/postcss) to 8.4.31 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 8.4.31
- [Release notes](https://github.com/postcss/postcss/releases)
- [Changelog](https://github.com/postcss/postcss/blob/main/CHANGELOG.md)
- [Commits](postcss/postcss@7.0.39...8.4.31)

Updates `css-loader` from 2.1.1 to 6.8.1
- [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@v2.1.1...v6.8.1)

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

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

fannie/modules/plugins2.0/MobileLane/package.json

@@ -9,7 +9,7 @@
     "babel-preset-es2015": "^6.14.0",
     "babel-preset-react": "^6.11.1",
     "bootstrap": "^3.3.7",
-    "css-loader": "^2.1.1",
+    "css-loader": "^6.8.1",
     "es6-promise": "~3.3.1",
     "jquery": "~3.5.0",
     "mobile-detect": "^1.4.4",