fix: update Next.js version in create-next-app (#57532)
### What?
The default template generated from `create-next-app` still says **Next.js 13**.
<img width="1053" alt="image" src="https://github.com/vercel/next.js/assets/2561973/1413dcda-d73d-43a9-ba47-8322cf193c52">
### Why?
Next.js 14 is released.
