fix(deps): update dependency next to v15.4.8 [security]

Author: renovate[bot]

package.json

@@ -28,7 +28,7 @@
     "livekit-client": "^2.13.3",
     "livekit-server-sdk": "^2.13.0",
     "motion": "^12.16.0",
-    "next": "15.4.7",
+    "next": "15.4.8",
     "next-themes": "^0.4.6",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",