Avoid OrderedIterator when comparing OpenApiSchema.Required equality (#57298)

* Avoid OrderedIterator when comparing OpenApiSchema.Required equality

* Fix typo

Author: captainsafia

src/OpenApi/src/Comparers/OpenApiSchemaComparer.cs

@@ -63,7 +63,7 @@ public bool Equals(OpenApiSchema? x, OpenApiSchema? y)
             x.Nullable == y.Nullable &&
             x.Pattern == y.Pattern &&
             x.ReadOnly == y.ReadOnly &&
-            x.Required.Order().SequenceEqual(y.Required.Order()) &&
+            x.Required.Count == y.Required.Count && x.Required.SetEquals(y.Required) &&
             OpenApiReferenceComparer.Instance.Equals(x.Reference, y.Reference) &&
             x.UniqueItems == y.UniqueItems &&
             x.UnresolvedReference == y.UnresolvedReference &&