### 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(nullptr);
	return camera_3d;
}
void Viewport::_camera_3d_transform_changed_notify() {
}
void Viewport::_camera_3d_set(Camera3D *p_camera) {
	if (camera_3d == p_camera) {
		return;
	}
	if (camera_3d) {
		camera_3d->notification(Camera3D::NOTIFICATION_LOST_CURRENT);
	}
	camera_3d = p_camera;
	if (!camera_3d_override) {
		if (camera_3d) {
			RenderingServer::get_singleton()->viewport_attach_camera(viewport, camera_3d->get_camera());
		} else {
			RenderingServer::get_singleton()->viewport_attach_camera(viewport, RID());
		}
	}
	if (camera_3d) {
		camera_3d->notification(Camera3D::NOTIFICATION_BECAME_CURRENT);
	}
	_update_audio_listener_3d();
	_camera_3d_transform_changed_notify();
}
bool Viewport::_camera_3d_add(Camera3D *p_camera) {