src/vs/base/browser/ui/dialog/dialog.ts/Dialog/dispose
class Dialog:	override dispose(): void {
		super.dispose();

		if (this.modalElement) {
			this.modalElement.remove();
			this.modalElement = undefined;
		}

		if (this.focusToReturn && isAncestor(this.focusToReturn, document.body)) {
			this.focusToReturn.focus();
			this.focusToReturn = undefined;
		}
	}