### 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.
#ifndef _3D_DISABLED
	if (!use_xr) {
#endif
		if (p_allocated) {
			RS::get_singleton()->viewport_set_size(viewport, size.width, size.height);
		} else {
			RS::get_singleton()->viewport_set_size(viewport, 0, 0);
		}
#ifndef _3D_DISABLED
	} 
#endif
	_update_global_transform();
	update_configuration_warnings();
	update_canvas_items();
	for (ViewportTexture *E : viewport_textures) {
		E->emit_changed();
	}
	emit_signal(SNAME("size_changed"));
	Rect2i limit = get_visible_rect();
	for (int i = 0; i < gui.sub_windows.size(); ++i) {
		Window *sw = gui.sub_windows[i].window;
		Rect2i rect = Rect2i(sw->position, sw->size);
		Rect2i new_rect = sw->fit_rect_in_parent(rect, limit);
		if (new_rect != rect) {
			sw->set_position(new_rect.position);
			sw->set_size(new_rect.size);
		}
	}
}
Size2i Viewport::_get_size() const {