chore(deps-dev): bump css-loader from 5.2.7 to 6.5.1

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 5.2.7 to 6.5.1.
- [Release notes](https://github.com/webpack-contrib/css-loader/releases)
- [Changelog](https://github.com/webpack-contrib/css-loader/blob/master/CHANGELOG.md)
- [Commits](webpack/css-loader@v5.2.7...v6.5.1)

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

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

Author: dependabot[bot]

package-lock.json

@@ -63,7 +63,7 @@
     "@workadventure/iframe-api-typings": "^1.7.2",
     "copy-webpack-plugin": "^9.0.1",
     "cross-env": "^7.0.3",
-    "css-loader": "^5.2.4",
+    "css-loader": "^6.5.1",
     "eslint": "^7.6.0",
     "fork-ts-checker-webpack-plugin": "^6.2.9",
     "html-webpack-plugin": "^5.3.1",