Bump css-loader from 6.11.0 to 7.0.0 in /mpcontribs-portal

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 6.11.0 to 7.0.0.
- [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@v6.11.0...v7.0.0)

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

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

mpcontribs-portal/package.json

@@ -29,7 +29,7 @@
     "clean-webpack-plugin": "^4.0.0",
     "compression-webpack-plugin": "^11.0.0",
     "core-js": "^3.33.1",
-    "css-loader": "^6.8.1",
+    "css-loader": "^7.0.0",
     "handsontable": "^13.1.0",
     "highlight.js": "^11.9.0",
     "imports-loader": "^5.0.0",