Bump cssnano from 4.1.11 to 6.0.1

Bumps [cssnano](https://github.com/cssnano/cssnano) from 4.1.11 to 6.0.1.
- [Release notes](https://github.com/cssnano/cssnano/releases)
- [Commits](https://github.com/cssnano/cssnano/compare/v4.1.11...cssnano@6.0.1)

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

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

package.json

@@ -52,7 +52,7 @@
     "compression-webpack-plugin": "^6.1.1",
     "cross-env": "^7.0.3",
     "css-loader": "^5.2.7",
-    "cssnano": "^4.1.11",
+    "cssnano": "^6.0.1",
     "detect-passive-events": "^2.0.3",
     "dotenv": "^16.0.3",
     "emoji-mart": "npm:emoji-mart-lazyload@latest",