nix/system/Pam.nix

{ ... }:
{
  security.pam.loginLimits = [
    {
      domain = "*";
      item = "nofile";
      type = "soft";
      value = "999999999";
    }
    {
      domain = "@users";
      item = "rtprio";
      type = "-";
      value = 1;
    }
  ];
}