[🐞] preloader script can contain duplicated keys

<img width="1512" height="909" alt="Image" src="https://github.com/user-attachments/assets/699e773e-c85d-4f88-9cf9-ee6a822853e8" />

This can increase the size of the html a little bit.

Repro: https://qwikified-threejs.vercel.app/ & https://github.com/maiieul/qwikified-threejs