fix(deps): update nextjs monorepo to v15

Author: renovate[bot]

package.json

@@ -35,7 +35,7 @@
     "github-slugger": "^2.0.0",
     "katex": "^0.16.11",
     "medium-zoom": "^1.1.0",
-    "next": "14.2.15",
+    "next": "15.1.0",
     "next-pwa": "^5.6.0",
     "next-themes": "^0.3.0",
     "nextjs-google-analytics": "^2.3.7",
@@ -51,7 +51,7 @@
     "swr": "^2.2.5"
   },
   "devDependencies": {
-    "@next/bundle-analyzer": "14.2.15",
+    "@next/bundle-analyzer": "15.1.0",
     "@syfxlin/eslint-config": "^1.0.8",
     "@types/fs-extra": "^11.0.4",
     "@types/katex": "^0.16.7",