Remove old relation hack for ignorning derived row number table.

Author: metaskills

lib/active_record/connection_adapters/sqlserver/core_ext/relation.rb

@@ -5,7 +5,6 @@
 require 'active_record/connection_adapters/sqlserver/core_ext/active_record'
 require 'active_record/connection_adapters/sqlserver/core_ext/explain'
 require 'active_record/connection_adapters/sqlserver/core_ext/explain_subscriber'
-require 'active_record/connection_adapters/sqlserver/core_ext/relation'
 require 'active_record/connection_adapters/sqlserver/core_ext/attribute_methods'
 require 'active_record/connection_adapters/sqlserver/version'
 require 'active_record/connection_adapters/sqlserver/type'