### 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)

ERR_READ_THREAD_GUARD_V(DEFAULT_CANVAS_ITEM_TEXTURE_REPEAT_DISABLED);
	return default_canvas_item_texture_repeat;
}
void Viewport::set_vrs_mode(Viewport::VRSMode p_vrs_mode) {
	ERR_MAIN_THREAD_GUARD;
	
	vrs_mode = p_vrs_mode;
	switch (p_vrs_mode) {
		case VRS_TEXTURE: {
			RS::get_singleton()->viewport_set_vrs_mode(viewport, RS::VIEWPORT_VRS_TEXTURE);
		} break;
		case VRS_XR: {
			RS::get_singleton()->viewport_set_vrs_mode(viewport, RS::VIEWPORT_VRS_XR);
		} break;
		default: {
			RS::get_singleton()->viewport_set_vrs_mode(viewport, RS::VIEWPORT_VRS_DISABLED);
		} break;
	}
	notify_property_list_changed();
}
Viewport::VRSMode Viewport::get_vrs_mode() const {