Update dependency cssnano to v8

Author: renovate[bot]

website/package.json

@@ -7,7 +7,7 @@
         "@fortawesome/fontawesome-free": "^7.0.0",
         "@tailwindcss/forms": "^0.5.0",
         "autoprefixer": "^10.4",
-        "cssnano": "^7.0.0",
+        "cssnano": "^8.0.0",
         "postcss": "^8.4.5",
         "postcss-cli": "^11.0.0",
         "postcss-import": "^16.0.0",