Release `hide_merge_requests_from_banned_users` feature flag

Why are we doing this work?

The hide_merge_requests_from_banned_users feature flag is currently enabled in staging and production. The code behind this feature flag was merged in December 2022 and the feature flag was enabled in January of 2023.

chatops	dev	staging	staging-ref	production
/chatops run feature get hide_merge_requests_from_banned_users --dev --staging --staging-ref --production	does not exist	enabled	does not exist	enabled

Relevant links

• Chatops
• Definition
• Rollout Issue
• Feature issue
• Introduced By

Implementation plan

• TBD

Verification steps

• This feature is only available for SaaS only. (i.e. This won't be available in self-managed for now)