[ruby|client] Fix unmarshalling errors of enums inside other objects

Ruby|Client autogenerated model classes for Enums do not expose openapi_one_of
method. Instead they expose openapi_any_of method like:

      # List of class defined in anyOf (OpenAPI v3)
      def openapi_any_of
        [
          :String
        ]
      end

Both types (objects and enums) do respond to build() method.

modules/openapi-generator/src/main/resources/ruby-client/base_object.mustache

@@ -63,7 +63,7 @@
       else # model
         # models (e.g. Pet) or oneOf
         klass = {{moduleName}}.const_get(type)
-        klass.respond_to?(:openapi_one_of) ? klass.build(value) : klass.build_from_hash(value)
+        klass.respond_to?(:openapi_any_of) || klass.respond_to?(:openapi_one_of) ? klass.build(value) : klass.build_from_hash(value)
       end
     end