Remove compiler feature detection for = delete

sky/engine/core/dom/Attr.h

Index: sky/engine/core/dom/Attr.h
diff --git a/sky/engine/core/dom/Attr.h b/sky/engine/core/dom/Attr.h
index 786ff35979f0d7c773d25b41f1aa7c46e24e0a08..b2eb4b5cef318fd446ffa9ef88110d7eda144adb 100644
--- a/sky/engine/core/dom/Attr.h
+++ b/sky/engine/core/dom/Attr.h
@@ -52,7 +52,7 @@ public:
 private:
     Attr(Element&, const QualifiedName&);
 
-    bool isElementNode() const WTF_DELETED_FUNCTION; // This will catch anyone doing an unnecessary check.
+    bool isElementNode() const = delete; // This will catch anyone doing an unnecessary check.
 
     virtual String nodeName() const override { return name(); }
     virtual NodeType nodeType() const override { return ATTRIBUTE_NODE; }