Add FF disable setting last_used_at on SSH access [RUN ALL RSPEC] [RUN AS-IF-FOSS]

Merged Bob Van Landuyt requested to merge bvl-disable-git-ssh-key-update into master

What does this MR do?

This allows circumventing setting the last_used_at flag when accessing repositories through git-ssh.

This is a band aid for gitlab-com/gl-infra/scalability#889 (moved)

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Edited by Bob Van Landuyt