[Feature flag] Cleanup of `ci-graphql-pipeline-mini-graph`

Summary

This issue is to cleanup the ci-graphql-pipeline-mini-graph feature flag, after the feature flag has been enabled by default for an appropriate amount of time in production.

Rollout issue

Architecture blueprint

Owners

• Team: Pipeline Authoring
• Most appropriate slack channel to reach out to: #g_pipeline-authoring
• Best individual to reach out to: @bsandlin
• PM: @dhershkovitch

Stakeholders

Pages will use the GraphQL pipeline mini graph:

• pipeline editor
• commit page
• merge request widget

Expectations

This will be blocked by multiple cleanup issues in the epic. Once those clean up issues are complete, we can consider this issue complete.

What might happen if this goes wrong?

The pipeline mini graph in the widgets could experience bugs

Cleaning up the feature flag

• Specify in the issue description if this feature will be removed completely or will be productized as part of the Feature Flag cleanup
• 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 --pre --staging --staging-ref --production
• Close this rollout issue.