Exporting a PackedScene in a custom Resource makes its custom icon to dissappear from the FileSystem

[z4gon]

Tested versions

• Reproducible in: 4.3.beta1.official [a4f2ea9]

System information

macOS Sonoma 14.1.1 - OpenGL API 4.1 Metal - 88 - Compatibility - Using Device: Apple - Apple M1 Pro

Issue description

Given a custom Resource like this:

@icon("res://icon.svg")

class_name MyResource
extends Resource

@export var my_value: int = 100
@export var my_scene: PackedScene 

Setting the value for my_scene in the Inspector like this:

Makes the custom icon to dissappear in the FileSystem:

Steps to reproduce

1. create an empty project
2. create a script extending Resource, give it class_name MyResource and an @icon("res://icon.svg")
3. make the resource export a PackedScene
4. create a my_resource_1.tres resource with the script MyResource
5. create a my_scene.tscn file, with a Sprite2D using an image different than the one used for @icon in the resource (I used this image)
6. reference this scene in my_resource_1.tres, save
7. observe the custom icon dissappearing from the FileSystem for my_resource_1.tres

Minimal reproduction project (MRP)

N/A