### 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)

if (co && co->can_process()) {
						new_collider = result.collider_id;
						if (!capture_object) {
							last_object = co;
							last_id = result.collider_id;
							if (co->get_capture_input_on_drag() && mb.is_valid() && mb->get_button_index() == MouseButton::LEFT && mb->is_pressed()) {
								physics_object_capture = last_id;
							}
						}
					}
					if (is_mouse && new_collider != physics_object_over) {
						if (physics_object_over.is_valid()) {
							CollisionObject3D *previous_co = Object::cast_to<CollisionObject3D>(ObjectDB::get_instance(physics_object_over));
							if (previous_co) {
								previous_co->_mouse_exit();
							}
						}
						if (new_collider.is_valid()) {
							DEV_ASSERT(co);
							co->_mouse_enter();
						}
						physics_object_over = new_collider;
					}
					if (capture_object) {
						_collision_object_3d_input_event(capture_object, camera_3d, ev, result.position, result.normal, result.shape);
					} else if (new_collider.is_valid()) {
						_collision_object_3d_input_event(co, camera_3d, ev, result.position, result.normal, result.shape);
					}
				}
				last_pos = pos;