### 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.
if (get_base_window() == p_window) {
		gui_release_focus();
	}
}
bool Viewport::_gui_control_has_focus(const Control *p_control) {
	return gui.key_focus == p_control;
}
void Viewport::_gui_control_grab_focus(Control *p_control) {
	if (gui.key_focus && gui.key_focus == p_control) {
		
		return;
	}
	get_tree()->call_group("_viewports", "_gui_remove_focus_for_window", (Node *)get_base_window());
	if (p_control->is_inside_tree() && p_control->get_viewport() == this) {
		gui.key_focus = p_control;
		emit_signal(SNAME("gui_focus_changed"), p_control);
		p_control->notification(Control::NOTIFICATION_FOCUS_ENTER);
		p_control->queue_redraw();
	}
}
void Viewport::_gui_accept_event() {
	gui.key_event_accepted = true;
	if (is_inside_tree()) {
		set_input_as_handled();
	}
}
void Viewport::_drop_mouse_over() {