refactor: add admin mode controller paths to rack attack defaults
In gitlab!16981 (merged) we've added new controller paths for admin mode session management. The new paths must be protected by Rack::Attack.
Related change to main gitlab app in gitlab!18214 (merged)
Fixes gitlab#36872 (closed)
The development of this MR is sponsored by Siemens (/cc @bufferoverflow)
Edited by Diego Louzán