Resolve "Geo: Disable updates to Key#last_used_at"

What does this MR do?

Skips updating Key#last_used_at on Geo secondaries

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Database updates performed in GET requests break Geo, and need individual workarounds.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by Backend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #3505 (closed)