build(deps-dev): bump css-loader from 6.8.1 to 7.1.1

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 6.8.1 to 7.1.1.
- [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@v6.8.1...v7.1.1)

---
updated-dependencies:
- dependency-name: css-loader
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

packages/purgecss-webpack-plugin/package.json

@@ -45,7 +45,7 @@
   },
   "devDependencies": {
     "@types/webpack-sources": "^3.2.0",
-    "css-loader": "^6.6.0",
+    "css-loader": "^7.1.1",
     "mini-css-extract-plugin": "^2.5.0"
   },
   "peerDependencies": {