Shallow clone node in _sanitizeAttributes
Shallow clone node in _sanitizeAttributes

Deep cloning (cloning all children along with the node) is unnecessary as only
the attributes are being used. Shallow cloning is much less expensive.

neilj/DOMPurify,voku/DOMPurify,voku/DOMPurify,Joris-van-der-Wel/DOMPurify,ConradIrwin/DOMPurify,kwangkim/DOMPurify,neilj/DOMPurify,togusafish/t-ashula-_-DOMPurify,neilj/DOMPurify,tdeekens/DOMPurify,tdeekens/DOMPurify,Joris-van-der-Wel/DOMPurify,ConradIrwin/DOMPurify,tdeekens/DOMPurify,togusafish/t-ashula-_-DOMPurify,kwangkim/DOMPurify,Joris-van-der-Wel/DOMPurify