Add maximum number of all logins on system
https://www.man7.org/linux/man-pages/man5/limits.conf.5.html
maxsyslogins maximum number of all logins on system; user is not allowed to log-in if total number of all user logins is greater than specified number (this limit does not apply to user with uid=0)
Proposed CLI
set system login max-login-session 2