fix(dev): handle relative baseURL

[danielroe]

🔗 Linked issue

related: https://github.com/nuxt/nuxt/issues/28474

❓ Type of change

• [ ] 📖 Documentation (updates to the documentation or readme)
• [x] 🐞 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

When passing a relative app.baseURL, this should not affect how the server is started. This applies the same fix in Nuxt runtimeConfig:

https://github.com/nuxt/nuxt/blob/d1c40328fe959f05ae77cc66311c40d5f151a109/packages/schema/src/config/nitro.ts#L18-L20