Godot version: 3.5

OS/device including version: Vita (tested from Windows and Linux builds, both hit this bug)

Issue description: After setting export assets (Bubble icon, app splash, Livearea BG, Livearea startup buttons) for a vita project, the VPK fails to install in vitashell with the error 0x8010113D.

Removing the export assets from the export selection boxes doesn't fix the bug as the VPK continues to use a cached version that still includes the export assets, even if you delete the original export asset files off your hard drive. (This is probably a separate bug that needs to be fixed)

I did figure out a workaround, which was to
a) remove the export assets from the export menu
b) delete the cached version, by deleting the ~/.cache/godot/app (C:\Users\<user>\AppData\Local\Godot\app on windows) folder and then re-export and install without any export assets set for the project.

Steps to reproduce:

1. Set export assets to .png files.
2. Export the project to a VPK.
3. Attempt to install the VPK in VitaShell.

Minimal reproduction project: N/A? This is an export bug