Raise NotImplementedError when using empty_insert_statement_value with Oracle

Refer: https://github.com/rsim/oracle-enhanced/pull/1180

activerecord/test/cases/dup_test.rb

@@ -143,6 +143,8 @@ def test_dup_with_default_scope
     end
 
     def test_dup_without_primary_key
+      skip if current_adapter?(:OracleAdapter)
+
       klass = Class.new(ActiveRecord::Base) do
         self.table_name = "parrots_pirates"
       end

activerecord/test/cases/primary_keys_test.rb

@@ -183,6 +183,8 @@ def test_primary_key_update_with_custom_key_name
   end
 
   def test_create_without_primary_key_no_extra_query
+    skip if current_adapter?(:OracleAdapter)
+
     klass = Class.new(ActiveRecord::Base) do
       self.table_name = "dashboards"
     end