### Godot version

v4.1.dev.custom_build [18112ba36]

### System information

Linux Mint 21.1, NVIDIA GeForce GTX 1050 Ti,  Vulkan API 1.3.205

### Issue description

This is a regression from #64388. 

Textures seem to be used differently in 2D and 3D. They are rendered using the `RID` in 3D, and changing the `viewport_path` will cause the `RID` to change.

https://github.com/godotengine/godot/assets/30386067/ad393fe8-50c1-4a89-870d-58d4e224bcc6


### Steps to reproduce

1. Download and import MRP.
2. Open 1.tscn, and try to switch the `viewport_path` of the `MeshInstance3D:mesh:material:albedo_texture` in the MeshInstance3D node.
3. After switching, the MeshInstance3D is rendered as white in the editor;
4. Close and then reopen 1.tscn.

### Minimal reproduction project

[ViewportTexture-change-viewport_path.zip](https://github.com/godotengine/godot/files/11509010/ViewportTexture-change-viewport_path.zip)

#ifndef _3D_DISABLED
	if (use_xr) {
		if (XRServer::get_singleton() != nullptr) {
			Ref<XRInterface> xr_interface = XRServer::get_singleton()->get_primary_interface();
			if (xr_interface.is_valid() && xr_interface->is_initialized()) {
				Size2 xr_size = xr_interface->get_render_target_size();
				return (Size2i)xr_size;
			}
		}
		return Size2i();
	}
#endif 
	return size;
}
Size2i Viewport::_get_size_2d_override() const {