chore(deps-dev): Bump next from 14.2.35 to 15.5.18 in /packages/nextjs

Bumps [next](https://github.com/vercel/next.js) from 14.2.35 to 15.5.18.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v14.2.35...v15.5.18)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.18
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

packages/nextjs/package.json

@@ -92,7 +92,7 @@
   },
   "devDependencies": {
     "eslint-plugin-react": "^7.31.11",
-    "next": "14.2.35",
+    "next": "15.5.18",
     "react": "^18.3.1",
     "react-dom": "^18.3.1"
   },