test: skip testUpgradeInstanceWithOldDataFs if WITH_LEGACY_WORKFLOW is False.

because it contains legacy workflow objects.
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-Master

failed ERP5.UnitTest-Master

failed ERP5.UnitTest-Master.Medusa

passed SlapOS.Eggs.UnitTest-Master.Python2

passed SlapOS.Eggs.UnitTest-Master.Python3