### 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)

PROJECTION_PERSPECTIVE,
			PROJECTION_ORTHOGONAL
		};
		Projection projection = Projection::PROJECTION_PERSPECTIVE;
		real_t fov = 0.0;
		real_t size = 0.0;
		real_t z_near = 0.0;
		real_t z_far = 0.0;
		RID rid;
		operator bool() const {
			return rid != RID();
		}
	} camera_3d_override;
	friend class Camera3D;
	Camera3D *camera_3d = nullptr;
	HashSet<Camera3D *> camera_3d_set;
	Camera3D *get_camera_3d() const;
	void _camera_3d_transform_changed_notify();
	void _camera_3d_set(Camera3D *p_camera);