Motivation for this change

https://jlk.fjfi.cvut.cz/arch/manpages/man/physlock.1.en

Enable -m Mute kernel messages on console while physlock is running. in

OPTIONS
-d Fork and detach physlock before prompting for authentication. The parent process returns right after everything is set up, so this option is useful for use in suspend/hibernate scripts.
-h Print brief usage information to standard output and exit.
-l Only lock console switching and exit.
-L Only enable (unlock) console switching and exit. This is useful when a prior instance of physlock has crashed and leaved the console switching mechanism locked.
-m Mute kernel messages on console while physlock is running.
-p MSG
Display MSG before the password prompt.
-s Disable SysRq mechanism while physlock is running.
-v Print version information to standard output and exit.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.