Remove reset_ci_minutes_for_all_namespaces FF

What does this MR do?

Closes #234067 (closed)

To be merged after September 1st (when we test this works on staging).

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• N/A Documentation (if required)
• N/A Code review guidelines
• N/A Merge request performance guidelines
• N/A Style guides
• N/A Database guides
• N/A Separation of EE specific content