Remove explicit require of factories

That's not needed anymore, as we're now using `.load_for` method.

See d2a1096

Author: waiting-for-dev

spec/support/spree.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require 'spree/testing_support/factories'
 require 'spree/testing_support/url_helpers'
 require 'spree/testing_support/controller_requests'
 require 'spree/testing_support/authorization_helpers'