[Feature flag] Cleanup ci_canceling_status
In [this issue](https://gitlab.com/gitlab-com/gl-infra/production/-/issues/17520) we released `ci_canceling_status` as default enabled to allow users to turn off the behavior if needed. We also documented that we will be removing the flag sometime in 17.1 or later so that users don't become overly dependent on the flag.
### Remove the flag
After the feature has been [deemed stable](https://about.gitlab.com/handbook/product-development-flow/feature-flag-lifecycle/#including-a-feature-behind-feature-flag-in-the-final-release), the [clean up](https://docs.gitlab.com/ee/development/feature_flags/controls.html#cleaning-up) should be done as soon as possible to permanently enable the feature and reduce complexity in the codebase.
You can either [create a follow-up issue for Feature Flag Cleanup](https://gitlab.com/gitlab-org/gitlab/-/issues/new?issuable_template=Feature%20Flag%20Cleanup) or use the checklist below in this same issue.
- [x] Create a merge request to remove `ci_canceling_status` feature flag. Ask for review and merge it.
- [x] Remove all references to the feature flag from the codebase.
- [x] Remove the YAML definitions for the feature from the repository.
- [x] Create [a changelog entry](https://docs.gitlab.com/ee/development/feature_flags/#changelog).
- [ ] Ensure that the cleanup MR has been included in the release package. If the merge request was deployed before [the monthly release was tagged](https://about.gitlab.com/handbook/engineering/releases/#self-managed-releases-1), the feature can be officially announced in a release blog post.
- [ ] `/chatops run release check <merge-request-url> <milestone>`
- [ ] Close [the feature issue](https://gitlab.com/groups/gitlab-org/-/epics/10158 "Ensure after_script is called for canceled jobs") to indicate the feature will be released in the current milestone.
- [ ] Clean up the feature flag from all environments by running these chatops command in `#production` channel:
- [ ] `/chatops run feature delete ci_canceling_status --dev --staging --staging-ref --production`
- [ ] Close this rollout issue.
<!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION -->
*This page may contain information related to upcoming products, features and functionality.
It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes.
Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.*
<!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION -->
issue