refactor: reorder template tag check to avoid expensive instanceof first

Co-authored-by: Ryan Christian <33403762+rschristian@users.noreply.github.com>

Author: frontman-git

src/diff/children.js

@@ -54,11 +54,11 @@ export function diffChildren(
 	refQueue
 ) {
 	if (
-		parentDom instanceof DocumentFragment &&
 		newParentVNode.type === 'template' &&
-		excessDomChildren?.length === 0
+		excessDomChildren?.length === 0 &&
+		parentDom instanceof DocumentFragment
 	) {
-		excessDomChildren = Array.from(parentDom.childNodes);
+		excessDomChildren = slice.call(parentDom.childNodes);
 	}
 	let i,
 		/** @type {VNode} */