Enable/depreciate ci_pipeline_persisted_stages
Based on https://gitlab.com/gitlab-org/gitlab-ce/issues/57487#note_140238869 we should make ci_pipeline_persisted_stages
default behavior. Either by turning it on by default or removing that flag (I'm not sure which as this is my first such request).
Scheduling this for %11.10 as that's the next release I can "touch" but if engineering wants to pull it forward, feel free