software/slapos-testing: be able to test with more recent python3

See merge request !1457
Status Job ID Name Coverage
  External
passed Cloudooo.UnitTest-Master

failed ERP5.StandaloneDeploymentScriptTest-Debian.Buster

15:02:32

failed ERP5.StandaloneDeploymentScriptTest-Debian.Buster.Master

failed SlapOS-Master.StandaloneDeploymentScriptTest-Debian.Buster

15:03:58

passed SlapOS.Eggs.UnitTest-Master.Python2

00:16:39

passed SlapOS.Eggs.UnitTest-Master.Python3

00:16:23

failed SlapOS.Eggs.UnitTest-Master.Python3Next

00:20:51

passed SlapOS.Theia.ResilienceTest-Master-ERP5

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster

15:01:54

failed Wendelin.StandaloneDeploymentScriptTest-Debian.Buster.Master

15:01:51

passed SlapOS.Eggs.UnitTest-Master.Python2

passed SlapOS.Eggs.UnitTest-Master.Python3

failed SlapOS.Eggs.UnitTest-Master.Python3Next