Bump next in the npm_and_yarn group across 1 directory

Bumps the npm_and_yarn group with 1 update in the / directory: [next](https://github.com/vercel/next.js).


Updates `next` from 15.5.6 to 15.5.9
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.5.6...v15.5.9)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.9
  dependency-type: direct:production
  dependency-group: npm_and_yarn
...

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

Author: dependabot[bot]

examples/redis-minimal/package.json

@@ -15,7 +15,7 @@
   "dependencies": {
     "@fortedigital/nextjs-cache-handler": "workspace:*",
     "ioredis": "^5.8.2",
-    "next": "^15.5.6",
+    "next": "^15.5.9",
     "react": "^19.2.3",
     "react-dom": "^19.2.3",
     "redis": "^5.10.0"