### 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.
} else {
			gui.subwindow_focused = nullptr;
		}
	}
	RenderingServer::get_singleton()->viewport_set_parent_viewport(p_window->viewport, p_window->parent ? p_window->parent->viewport : RID());
}
int Viewport::_sub_window_find(Window *p_window) {
	for (int i = 0; i < gui.sub_windows.size(); i++) {
		if (gui.sub_windows[i].window == p_window) {
			return i;
		}
	}
	return -1;
}
void Viewport::_update_viewport_path() {
	if (viewport_textures.is_empty()) {
		return;
	}
	Node *scene_root = get_scene_file_path().is_empty() ? get_owner() : this;
	if (!scene_root && is_inside_tree()) {
		scene_root = get_tree()->get_edited_scene_root();
	}
	if (scene_root && (scene_root == this || scene_root->is_ancestor_of(this))) {
		NodePath path_in_scene = scene_root->get_path_to(this);
		for (ViewportTexture *E : viewport_textures) {
			E->path = path_in_scene;
		}
	}
}
void Viewport::_notification(int p_what) {