fix: update to latest @nuxt/module-builder

[danielroe]

🔗 Linked issue

❓ Type of change

• 📖 Documentation (updates to the documentation, readme or JSDoc annotations)
• 🐞 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)
• 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Previous versions of @nuxt/module-builder produced incorrect types for files in the runtime/ directory. Specifically, a .d.ts declaration paired with a .mjs file. This isn't correct - it should be either .d.mts and .mjs or .d.ts and .js.

For maximum compatibility, @nuxt/module-builder v0.8 switched to .js extension for files in runtime/ directory.

With the latest Nuxt, this is now an error that removes correct plugin injection types.

Related PRs: nuxt/nuxt#28480, nuxt/nuxt#28593
See also nuxt/nuxt#28672.

📝 Checklist

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