### Godot version

v4.0 rc6

### System information

Windows 10

### Issue description

When using a ViewportTexture from a SubViewport on a TextureRect, it throws errors after running the scene once and then switching scenes in the editor.
![Pasted image 20230227212626](https://user-images.githubusercontent.com/44676282/221680047-984fa03e-33d1-4856-9a7f-1700b28423cf.png)


### Steps to reproduce

Run the canvas-scene once.
Switch to another scene in the editor.
Switch back to the canvas-scene

### Minimal reproduction project

[ViewportTextureError.zip](https://github.com/godotengine/godot/files/10844099/ViewportTextureError.zip)

List<PropertyInfo> plist;
	get_property_list(&plist);
	Ref<Resource> r = static_cast<Resource *>(ClassDB::instantiate(get_class()));
	ERR_FAIL_COND_V(r.is_null(), Ref<Resource>());
	for (const PropertyInfo &E : plist) {
		if (!(E.usage & PROPERTY_USAGE_STORAGE)) {
			continue;
		}
		Variant p = get(E.name);
		switch (p.get_type()) {
			case Variant::Type::DICTIONARY: