Serialize type array in v31

Author: MaggieKimani1

src/Microsoft.OpenApi/Models/OpenApiSchema.cs

@@ -339,6 +339,7 @@ public OpenApiSchema(OpenApiSchema schema)
             V31ExclusiveMaximum = schema?.V31ExclusiveMaximum ?? V31ExclusiveMaximum;
             V31ExclusiveMinimum = schema?.V31ExclusiveMinimum ?? V31ExclusiveMinimum;
             Type = schema?.Type ?? Type;
+            TypeArray = schema.TypeArray != null ? new string[schema.TypeArray.Length] : null;
             Format = schema?.Format ?? Format;
             Description = schema?.Description ?? Description;
             Maximum = schema?.Maximum ?? Maximum;
@@ -575,6 +576,7 @@ public void SerializeAsV2(IOpenApiWriter writer)
         internal void WriteV31Properties(IOpenApiWriter writer)
         {
             writer.WriteProperty(OpenApiConstants.DollarSchema, Schema);
+            writer.WriteOptionalCollection(OpenApiConstants.TypeArray, TypeArray, (w, s) => w.WriteRaw(s));
             writer.WriteProperty(OpenApiConstants.Id, Id);
             writer.WriteProperty(OpenApiConstants.Comment, Comment);
             writer.WriteProperty(OpenApiConstants.Vocabulary, Vocabulary);