### 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.
ERR_READ_THREAD_GUARD_V(false);
	return physics_object_picking;
}
void Viewport::set_physics_object_picking_sort(bool p_enable) {
	ERR_MAIN_THREAD_GUARD;
	physics_object_picking_sort = p_enable;
}
bool Viewport::get_physics_object_picking_sort() {
	ERR_READ_THREAD_GUARD_V(false);
	return physics_object_picking_sort;
}
Vector2 Viewport::get_camera_coords(const Vector2 &p_viewport_coords) const {
	ERR_READ_THREAD_GUARD_V(Vector2());
	Transform2D xf = stretch_transform * global_canvas_transform;
	return xf.xform(p_viewport_coords);
}
Vector2 Viewport::get_camera_rect_size() const {
	ERR_READ_THREAD_GUARD_V(Vector2());
	return size;
}
void Viewport::set_disable_input(bool p_disable) {