chore(deps): bump next from 15.5.5 to 15.5.6 (#5336)

Bumps [next](https://github.com/vercel/next.js) from 15.5.5 to 15.5.6.
- [Release notes](https://github.com/vercel/next.js/releases)
- [Changelog](https://github.com/vercel/next.js/blob/canary/release.js)
- [Commits](vercel/next.js@v15.5.5...v15.5.6)

---
updated-dependencies:
- dependency-name: next
  dependency-version: 15.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

package-lock.json

@@ -12,7 +12,7 @@
     "start": "next start"
   },
   "dependencies": {
-    "next": "15.5.5",
+    "next": "15.5.6",
     "react": "18.3.1",
     "react-dom": "18.3.1"
   },

showcases/next-showcase/package.json

@@ -25,7 +25,7 @@
   "dependencies": {
     "dompurify": "3.3.0",
     "highlight.js": "11.11.1",
-    "next": "15.5.5",
+    "next": "15.5.6",
     "react": "18.3.1",
     "react-archer": "4.4.0",
     "react-dom": "18.3.1",