### 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)

ClassDB::bind_method(D_METHOD("get_texture"), &Viewport::get_texture);
	ClassDB::bind_method(D_METHOD("set_physics_object_picking", "enable"), &Viewport::set_physics_object_picking);
	ClassDB::bind_method(D_METHOD("get_physics_object_picking"), &Viewport::get_physics_object_picking);
	ClassDB::bind_method(D_METHOD("set_physics_object_picking_sort", "enable"), &Viewport::set_physics_object_picking_sort);
	ClassDB::bind_method(D_METHOD("get_physics_object_picking_sort"), &Viewport::get_physics_object_picking_sort);
	ClassDB::bind_method(D_METHOD("get_viewport_rid"), &Viewport::get_viewport_rid);
	ClassDB::bind_method(D_METHOD("push_text_input", "text"), &Viewport::push_text_input);
	ClassDB::bind_method(D_METHOD("push_input", "event", "in_local_coords"), &Viewport::push_input, DEFVAL(false));
#ifndef DISABLE_DEPRECATED
	ClassDB::bind_method(D_METHOD("push_unhandled_input", "event", "in_local_coords"), &Viewport::push_unhandled_input, DEFVAL(false));
#endif 
	ClassDB::bind_method(D_METHOD("get_camera_2d"), &Viewport::get_camera_2d);
	ClassDB::bind_method(D_METHOD("set_as_audio_listener_2d", "enable"), &Viewport::set_as_audio_listener_2d);
	ClassDB::bind_method(D_METHOD("is_audio_listener_2d"), &Viewport::is_audio_listener_2d);
	ClassDB::bind_method(D_METHOD("get_mouse_position"), &Viewport::get_mouse_position);
	ClassDB::bind_method(D_METHOD("warp_mouse", "position"), &Viewport::warp_mouse);
	ClassDB::bind_method(D_METHOD("update_mouse_cursor_state"), &Viewport::update_mouse_cursor_state);
	ClassDB::bind_method(D_METHOD("gui_get_drag_data"), &Viewport::gui_get_drag_data);
	ClassDB::bind_method(D_METHOD("gui_is_dragging"), &Viewport::gui_is_dragging);
	ClassDB::bind_method(D_METHOD("gui_is_drag_successful"), &Viewport::gui_is_drag_successful);
	ClassDB::bind_method(D_METHOD("gui_release_focus"), &Viewport::gui_release_focus);
	ClassDB::bind_method(D_METHOD("gui_get_focus_owner"), &Viewport::gui_get_focus_owner);
	ClassDB::bind_method(D_METHOD("set_disable_input", "disable"), &Viewport::set_disable_input);
	ClassDB::bind_method(D_METHOD("is_input_disabled"), &Viewport::is_input_disabled);
	ClassDB::bind_method(D_METHOD("_gui_remove_focus_for_window"), &Viewport::_gui_remove_focus_for_window);
	ClassDB::bind_method(D_METHOD("_post_gui_grab_click_focus"), &Viewport::_post_gui_grab_click_focus);
	ClassDB::bind_method(D_METHOD("set_positional_shadow_atlas_size", "size"), &Viewport::set_positional_shadow_atlas_size);
	ClassDB::bind_method(D_METHOD("get_positional_shadow_atlas_size"), &Viewport::get_positional_shadow_atlas_size);
	ClassDB::bind_method(D_METHOD("set_positional_shadow_atlas_16_bits", "enable"), &Viewport::set_positional_shadow_atlas_16_bits);
	ClassDB::bind_method(D_METHOD("get_positional_shadow_atlas_16_bits"), &Viewport::get_positional_shadow_atlas_16_bits);