fix: match signature for nitro/nuxt useRuntimeConfigcomposables

[wattanx]

🔗 Linked issue

Fixes: #1229

❓ 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 like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

This is caused by a mismatch in the sigunature of useRuntimeConfig in Nitro and Nuxt.
This is the same way as upstream.
nuxt/nuxt#25440

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.