Missing files in the rive extension template

[maelig.moreau]

To reproduce:

• Create a new project
• Ad https://github.com/defold/extension-rive/archive/refs/tags/1.2.zip to dependencies
• Fetch libraries
• Bundle

Missing assets, prevents bundling

Context:

I tried to modify the zip file of the extension found in .internal and strangely the files are actually there, but as you can see the editor doesn’t seem to share this opinion.