chore(deps): update dependency next to v15.5.8 [security]

Author: renovate[bot]

packages/website/package.json

@@ -19,7 +19,7 @@
     "@types/react-dom": "19.2.3",
     "@uiw/react-codemirror": "4.25.3",
     "clsx": "2.1.1",
-    "next": "15.5.7",
+    "next": "15.5.8",
     "next-themes": "0.4.6",
     "nextra": "3.3.1",
     "nextra-theme-docs": "3.3.1",