[Feature flag] Cleanup overage_members_modal

Summary

Update 2024-05-29

Most of the work for this has been completed in !138580 (closed). We just fix conflicts and test with the recreation steps here #435230 (closed)

---

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

Main epic

Modal that informs users of additional charges before adding a member.

Owners

• Team: ~"group::billing and subscription management"
• Most appropriate slack channel to reach out to: #g_billing_and_subscription_management
• Best individual to reach out to: @dzubova
• PM: @tgolubeva

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.