[Feature flag] Cleanup artifacts_management_page feature flag

Summary

This issue is to cleanup the artifacts_management_page feature flag, after the feature flag has been enabled by default for an appropriate amount of time in production.

Enabling this feature flag allows access to a page where browse-able artifact files are listed for each job. To get to this page, navigate to a project, then choose CI/CD => Artifacts in the sidebar (or Build => Artifacts with the new navigation). If the user has permission to delete artifacts (project maintainer role or higher), they can also do that on this page.

• Feature issue: #33418 (closed)
• Feature flag rollout issue: #254938 (closed)

Owners

• Team: grouppipeline security
• Most appropriate slack channel to reach out to: #g_pipeline-security
• Best individual to reach out to: @mfluharty
• PM: @jocelynjane

Stakeholders

Expectations

What might happen if this goes wrong?

Cleaning up the feature flag

• Create a merge request to remove <feature-flag-name> feature flag. Ask for review and merge it.
  • Remove all references to the feature flag from the codebase.
  • Remove the YAML definitions for the feature from the repository.
  • Create a changelog entry.
• Ensure that the cleanup MR has been deployed to both production and canary. If the merge request was deployed before the code cutoff, the feature can be officially announced in a release blog post.
  • /chatops run auto_deploy status <merge-commit-of-cleanup-mr>
• Close the feature issue to indicate the feature will be released in the current milestone.
• If not already done, clean up the feature flag from all environments by running these chatops command in #production channel:
  • /chatops run feature delete <feature-flag-name> --dev
  • /chatops run feature delete <feature-flag-name> --staging
  • /chatops run feature delete <feature-flag-name>
• Close this rollout issue.