fix transaction and savepoint AR tests, issues caused by a pull request

Omit BEGIN/COMMIT statements for empty transactions

rails/rails#32647

Author: JesseChavez

lib/arjdbc/mssql/adapter.rb

@@ -97,6 +97,14 @@ def supports_transaction_isolation?
         true
       end
 
+      def supports_savepoints?
+        true
+      end
+
+      def supports_lazy_transactions?
+        true
+      end
+
       # The MSSQL datetime type doe have precision.
       def supports_datetime_with_precision?
         true