Failed loading resources on web on converted project from Godot 4.1 to 4.3

### Tested versions

Reproducible on 4.3

### System information

Windows 11. Godot 4.3 dev Compatibility

### Issue description

I'm trying to use the Kenney Platformer Starter Kit 3d, I even developed a tech demo for my app for it, and it looks and work fine on godot editor, but when exported to web all models are white because they are missing the textures. I tried with the tool to convert texture but is doing nothing. The kenney platformer starter kit I think is godot 4.0 or 4.1, so I had to convert it to 4.3 to be able to export to web with no threads.


### Steps to reproduce

- Download Kenneys platformer starter template: https://github.com/KenneyNL/Starter-Kit-3D-Platformer
- Open it on Godot 4.3
- Export to web
- You can see is missing textures, is all white, but on editor it looks fine.

### Minimal reproduction project (MRP)

https://github.com/KenneyNL/Starter-Kit-3D-Platformer

Start with the linked Kenney Starter-Kit-3D-Platformer minimal reproduction project and reproduce its Godot 4.3 web export. Compare the editor result with the exported build and investigate the texture conversion tool; done means the exported web project displays the models with their textures instead of rendering them white.

Written by the indexing model from the issue text.