[11.x] Fix sync is running touch query twice

[Tofandel]

The sync method is running touch operations twice if there is items to detach, which duplicates update queries

As we can see a little bit further in the sync method

        if (count($changes['attached']) ||
            count($changes['updated']) ||
            count($changes['detached'])) {
            $this->touchIfTouching();
        }

So the sync method already takes care of touchIfTouching so we do not need to run it in detach