playbook: cleanup slapcache roles

We are now using recent enough ansible to always use succeeded keyword.

Also this fixes a leftover include.
3 jobs for master in 0 seconds
Status Job ID Name Coverage
  External
failed ERP5.StandaloneDeploymentScriptTest-Debian.Bulleseye.JEROME

15:03:26

passed ERP5.StandaloneDeploymentScriptTest-Debian.Buster

00:31:29

passed Wendelin.StandaloneDeploymentScriptTest-Debian.Bullseye

00:41:43