LibJS: Convert WeakSet::create() to NonnullGCPtr

Userland/Libraries/LibJS/Runtime/WeakSet.cpp

@@ -8,9 +8,9 @@
 
 namespace JS {
 
-WeakSet* WeakSet::create(Realm& realm)
+NonnullGCPtr<WeakSet> WeakSet::create(Realm& realm)
 {
-    return realm.heap().allocate<WeakSet>(realm, *realm.intrinsics().weak_set_prototype());
+    return *realm.heap().allocate<WeakSet>(realm, *realm.intrinsics().weak_set_prototype());
 }
 
 WeakSet::WeakSet(Object& prototype)

Userland/Libraries/LibJS/Runtime/WeakSet.h

@@ -19,7 +19,7 @@ class WeakSet final
     JS_OBJECT(WeakSet, Object);
 
 public:
-    static WeakSet* create(Realm&);
+    static NonnullGCPtr<WeakSet> create(Realm&);
 
     virtual ~WeakSet() override = default;