Update tailwindcss monorepo to v4.1.6

Author: renovate[bot]

apps/docs/package.json

@@ -47,13 +47,13 @@
   },
   "devDependencies": {
     "@next/eslint-plugin-next": "15.3.0",
-    "@tailwindcss/postcss": "4.1.3",
+    "@tailwindcss/postcss": "4.1.6",
     "@types/node": "22.14.1",
     "@types/react": "19.1.0",
     "@types/react-dom": "19.1.2",
     "pagefind": "1.3.0",
     "postcss": "8.5.3",
-    "tailwindcss": "4.1.3",
+    "tailwindcss": "4.1.6",
     "typescript": "5.8.3",
     "unist-builder": "4.0.0",
     "unist-util-visit": "5.0.0"