[FF] `merge_request_ready_flow_trigger`
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This is a rollout issue for `merge_request_ready_flow_trigger` feature flag that was added in [this MR](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/233605).
**Related:**
- https://gitlab.com/gitlab-org/gitlab/-/work_items/593564
- https://gitlab.com/gitlab-org/gitlab/-/merge_requests/228912
issue