fix(deps): update dependency next to v15.5.6 (#2264)

This PR contains the following updates:

| Package | Change | Age | Confidence |
|---|---|---|---|
| [next](https://nextjs.org)
([source](https://redirect.github.com/vercel/next.js)) | [`15.5.5` ->
`15.5.6`](https://renovatebot.com/diffs/npm/next/15.5.5/15.5.6) |
[![age](https://developer.mend.io/api/mc/badges/age/npm/next/15.5.6?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/next/15.5.5/15.5.6?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|

---

### Release Notes

<details>
<summary>vercel/next.js (next)</summary>

###
[`v15.5.6`](https://redirect.github.com/vercel/next.js/releases/tag/v15.5.6)

[Compare
Source](https://redirect.github.com/vercel/next.js/compare/v15.5.5...v15.5.6)

> \[!NOTE]\
> This release is backporting bug fixes. It does **not** include all
pending features/changes on canary.

##### Core Changes

- Turbopack: don't define process.cwd() in node\_modules
[#&#8203;83452](https://redirect.github.com/vercel/next.js/issues/83452)

##### Credits

Huge thanks to [@&#8203;mischnic](https://redirect.github.com/mischnic)
for helping!

</details>

---

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packages/examples/create-next-app-example/package-lock.json

@@ -10,7 +10,7 @@
   },
   "dependencies": {
     "cross-env": "7.0.3",
-    "next": "15.5.5",
+    "next": "15.5.6",
     "react": "19.2.0",
     "react-dom": "19.2.0"
   }

packages/examples/create-next-app-example/package.json

@@ -10,7 +10,7 @@
     "start": "cross-env HELLO=import-meta-env SECRET1=secret1 import-meta-env -x .env.example.public && cross-env SECRET1=secret1 SECRET2=secret2 next start -p 4173"
   },
   "dependencies": {
-    "next": "15.5.5",
+    "next": "15.5.6",
     "react": "18.3.1",
     "react-dom": "18.3.1",
     "swr": "2.3.6"