build(deps): bump next from 15.5.3 to 15.5.7

Bumps [next](https://github.com/vercel/next.js) from 15.5.3 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@v15.5.3...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]

packages/openapi-fetch/examples/nextjs/package.json

@@ -6,7 +6,7 @@
     "dev": "next dev"
   },
   "dependencies": {
-    "next": "^15.5.3",
+    "next": "^15.5.7",
     "openapi-fetch": "workspace:^",
     "react": "^18.3.1",
     "react-dom": "^18.3.1"