component/zodbtools: update py3 test to use ZODB6

We are using ZODB6 in ERP5 py3
Status Job ID Name Coverage
  External
failed Zodbtools.UnitTest-Master.ZODB4.Python2

00:00:48

passed Zodbtools.UnitTest-Master.ZODB5.Python2

00:00:53

failed Zodbtools.UnitTest-Master.ZODB6.Python3

00:00:45

failed Zodbtools.UnitTest-Master.ZODB4.Python2

00:00:57

passed Zodbtools.UnitTest-Master.ZODB5.Python2

00:30:35

failed Zodbtools.UnitTest-Master.ZODB6.Python3

00:00:53