Set adapter specific valid_column_definition_options

See rails/rails#46178
and rails/rails#47609

These were the options that were failing in the test suite.

lib/active_record/connection_adapters/oracle_enhanced/schema_definitions.rb

@@ -81,6 +81,11 @@ def references(*args, **options)
           super(*args, type: :integer, **options)
         end
         alias :belongs_to :references
+
+        private
+        def valid_column_definition_options
+          super + [:sequence_name, :as, :sequence_start_value, :type]
+        end
       end
 
       class AlterTable < ActiveRecord::ConnectionAdapters::AlterTable