refactor: drop 'closest' polyfill for IE
refactor: drop 'closest' polyfill for IE

ng-bootstrap/ng-bootstrap,fbasso/ng-bootstrap,ng-bootstrap/ng-bootstrap,jnizet/ng-bootstrap,ng-bootstrap/ng-bootstrap,jnizet/ng-bootstrap,fbasso/ng-bootstrap,fbasso/ng-bootstrap,jnizet/ng-bootstrap,ng-bootstrap/ng-bootstrap,jnizet/ng-bootstrap,fbasso/ng-bootstrap