Set immutable users in impermanence module.

hosts/common/impermanence.nix

@@ -23,6 +23,8 @@
   fileSystems."/var/log".options = ["compress=zstd" "noatime" ];
   fileSystems."/var/log".neededForBoot = true;
 
+  users.mutableUsers = false;
+
   # rollback results in sudo lectures after each reboot
   security.sudo.extraConfig = ''
     Defaults lecture = never

hosts/common/user-ppetru.nix

@@ -1,5 +1,4 @@
 {
-  users.mutableUsers = false;
   users.users.ppetru = {
     isNormalUser = true;
     extraGroups = [ "wheel" ];