Bump next in /examples/next/apollo-client-data-fetch/example-app

Bumps [next](https://github.com/vercel/next.js) from 15.5.2 to 15.5.7.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.5.2...v15.5.7)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.7
  dependency-type: direct:production
...

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

Author: dependabot[bot]

examples/next/apollo-client-data-fetch/example-app/package-lock.json

@@ -13,7 +13,7 @@
     "crypto-hash": "^3.1.0",
     "debounce": "^2.2.0",
     "graphql": "^16.10.0",
-    "next": "^15.5.2",
+    "next": "^15.5.7",
     "react": "^19.0.0",
     "react-dom": "^19.0.0"
   },