LibWeb: Make factory method of DOM::DOMTokenList fallible

Author: https://github.com/kennethmyhra
Commit: 251c063897
Pull-request: https://github.com/SerenityOS/serenity/pull/17491
Reviewed-by: https://github.com/linusg ✅

Userland/Libraries/LibWeb/DOM/DOMTokenList.h

@@ -23,7 +23,7 @@ class DOMTokenList final : public Bindings::LegacyPlatformObject {
     WEB_PLATFORM_OBJECT(DOMTokenList, Bindings::LegacyPlatformObject);
 
 public:
-    static DOMTokenList* create(Element const& associated_element, DeprecatedFlyString associated_attribute);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<DOMTokenList>> create(Element const& associated_element, DeprecatedFlyString associated_attribute);
     ~DOMTokenList() = default;
 
     void associated_attribute_changed(StringView value);