Remove of the use_delete_tags_service_on_destroy_service feature flag

What does this MR do and why?

This feature has been rolled out to production 100% last December 1. As part of the issue, we would like to cleanup this feature flag.

• Feature issue: #375604 (closed)
• Rollout issue: #381445 (closed)
• Cleanup issue: #384534 (closed)

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

When deleting container repositories, it would call a DELETE on /tags/reference/<tag-name> instead of a DELETE on /manifest/<digest>.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.