Reduce unnecessary reliance on setuid binaries on my Linux hosts

[kergoth]

• sudo: https://tim.siosm.fr/blog/2023/12/19/ssh-over-unix-socket/
  • See also userv
  • See also sudon't
  • See also run0
• chsh: https://tim.siosm.fr/blog/2023/12/22/dont-change-defaut-login-shell/

"@siosm btw, the nicest way to disable the suid binaries is by dropping in a config snippet for systemd that sets NoNewPriviliges=yes, system wide. In that case suid is a thing of the past. (I mean, ideally we'd have an option to compile it out of the kernel, but this is the next best thing)"