Rollout the `ci_atomic_processing` and `ci_composite_status` feature flag
### Problem to solve
We merged the https://gitlab.com/gitlab-org/gitlab/issues/30656. Which is a first step towards atomic processing of pipelines.
This issue is to track the rollout of the feature once we continue working on https://gitlab.com/gitlab-org/gitlab/issues/197365.
### Links / references
- https://gitlab.com/gitlab-org/gitlab/issues/30656
- https://gitlab.com/gitlab-org/gitlab/issues/197365
issue