fix(cli): use @nuxt/kit to load nuxt config

[danielroe]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality)
• ✨ New feature (a non-breaking change that adds functionality)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

using jiti to import nuxt.config would have issues with undefined defineNuxtConfig.

Using loadNuxtConfig also allows us to respect (and identify!) whether layers have disabled telemetry