build: Bump css-loader from 5.2.7 to 6.7.3

Bumps [css-loader](https://github.com/webpack-contrib/css-loader) from 5.2.7 to 6.7.3.
- [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@v5.2.7...v6.7.3)

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

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

package.json

@@ -58,7 +58,7 @@
     "babel-loader": "^8.2.2",
     "copy-webpack-plugin": "^8.1.1",
     "core-js": "^3.12.1",
-    "css-loader": "^5.2.4",
+    "css-loader": "^6.7.3",
     "eslint": "^7.26.0",
     "eslint-config-prettier": "^8.3.0",
     "eslint-plugin-import": "^2.22.1",

packages/mandelbrot/package.json

@@ -34,7 +34,7 @@
     "babel-loader": "^8.2.2",
     "copy-webpack-plugin": "^8.1.1",
     "core-js": "^3.12.1",
-    "css-loader": "^5.2.4",
+    "css-loader": "^6.7.3",
     "expose-loader": "^2.0.0",
     "file-loader": "^6.2.0",
     "globby": "^11.0.3",