chore(deps): update dependency tailwindcss to v4

Author: renovate[bot]

nextjs/package-lock.json

@@ -75,7 +75,7 @@
     "stylelint-config-standard": "40.0.0",
     "stylelint-order": "^8.0.0",
     "stylelint-webpack-plugin": "5.1.0",
-    "tailwindcss": "3.4.19",
+    "tailwindcss": "4.2.1",
     "typescript": "5.9.3"
   },
   "overrides": {