### 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.
return size_2d_override;
}
bool Viewport::_is_size_allocated() const {
	return size_allocated;
}
Rect2 Viewport::get_visible_rect() const {
	ERR_READ_THREAD_GUARD_V(Rect2());
	Rect2 r;
	if (size == Size2()) {
		r = Rect2(Point2(), DisplayServer::get_singleton()->window_get_size());
	} else {
		r = Rect2(Point2(), size);
	}
	if (size_2d_override != Size2i()) {
		r.size = size_2d_override;
	}
	return r;
}
void Viewport::canvas_parent_mark_dirty(Node *p_node) {