### Godot version

4.0.3-stable

### System information

Windows 10

### Issue description

In some projects ViewportTexture remains pink and doesn't render viewport content after upgrading from 4.0.2-stable to 4.0.3-stable. If a pair of files viewport.h/viewport.cpp are downgraded back to what they were in 4.0.2-stable, problem goes away.

This is how it looks in 4.0.3-stable:
![4 0 3_stable_viewport_4 0 3](https://github.com/godotengine/godot/assets/1449921/44c191a9-4b67-4b02-90b6-4ab615f62a73)

And this is how it looks if viewport.h/viewport.cpp are downgraded back to what they were in 4.0.2-stable.
![4 0 3_stable_viewport_4 0 2](https://github.com/godotengine/godot/assets/1449921/f5abc605-f129-4222-9c0e-e9a07621dd9d)



### Steps to reproduce

Unfortunately, I cannot come up wit a simple demo project reproducing the problem. It exists in some projects and doesn't exist in others.


### Minimal reproduction project

Cannot produce a simple project reproducing the problem. In simple projects it works fine.
} break;
		case NOTIFICATION_INTERNAL_PHYSICS_PROCESS: {
			if (!get_tree()) {
				return;
			}
			if (get_tree()->is_debugging_collisions_hint() && contact_2d_debug.is_valid()) {
				RenderingServer::get_singleton()->canvas_item_clear(contact_2d_debug);
				RenderingServer::get_singleton()->canvas_item_set_draw_index(contact_2d_debug, 0xFFFFF); 
				Vector<Vector2> points = PhysicsServer2D::get_singleton()->space_get_contacts(find_world_2d()->get_space());
				int point_count = PhysicsServer2D::get_singleton()->space_get_contact_count(find_world_2d()->get_space());
				Color ccol = get_tree()->get_debug_collision_contact_color();
				for (int i = 0; i < point_count; i++) {
					RenderingServer::get_singleton()->canvas_item_add_rect(contact_2d_debug, Rect2(points[i] - Vector2(2, 2), Vector2(5, 5)), ccol);
				}
			}
#ifndef _3D_DISABLED
			if (get_tree()->is_debugging_collisions_hint() && contact_3d_debug_multimesh.is_valid()) {
				Vector<Vector3> points = PhysicsServer3D::get_singleton()->space_get_contacts(find_world_3d()->get_space());
				int point_count = PhysicsServer3D::get_singleton()->space_get_contact_count(find_world_3d()->get_space());
				RS::get_singleton()->multimesh_set_visible_instances(contact_3d_debug_multimesh, point_count);
				for (int i = 0; i < point_count; i++) {
					Transform3D point_transform;
					point_transform.origin = points[i];
					RS::get_singleton()->multimesh_instance_set_transform(contact_3d_debug_multimesh, i, point_transform);
				}
			}
#endif 
		} break;
		case NOTIFICATION_VP_MOUSE_ENTER: {
			gui.mouse_in_viewport = true;