build(deps-dev): bump cssnano from 6.0.1 to 7.0.6

Bumps [cssnano](https://github.com/cssnano/cssnano) from 6.0.1 to 7.0.6.
- [Release notes](https://github.com/cssnano/cssnano/releases)
- [Commits](https://github.com/cssnano/cssnano/compare/[email protected]@7.0.6)

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

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

package.json

@@ -59,7 +59,7 @@
     "autoprefixer": "^10.4.13",
     "browserslist": "~4.22.1",
     "chromatic": "~9.0.0",
-    "cssnano": "^6.0.1",
+    "cssnano": "^7.0.6",
     "eslint": "^8.57.0",
     "eslint-config-airbnb": "^19.0.4",
     "eslint-config-airbnb-typescript": "^17.1.0",