treewide: use attrs instead of list for types.loaOf options

nixos/modules/services/security/clamav.nix

@@ -83,18 +83,15 @@ in
   config = mkIf (cfg.updater.enable || cfg.daemon.enable) {
     environment.systemPackages = [ pkg ];
 
-    users.users = singleton {
-      name = clamavUser;
+    users.users.${clamavUser} = {
       uid = config.ids.uids.clamav;
       group = clamavGroup;
       description = "ClamAV daemon user";
       home = stateDir;
     };
 
-    users.groups = singleton {
-      name = clamavGroup;
-      gid = config.ids.gids.clamav;
-    };
+    users.groups.${clamavGroup} =
+      { gid = config.ids.gids.clamav; };
 
     environment.etc."clamav/freshclam.conf".source = freshclamConfigFile;
     environment.etc."clamav/clamd.conf".source = clamdConfigFile;

nixos/modules/services/security/fprot.nix

@@ -48,22 +48,18 @@ in {
     services.fprot.updater.licenseKeyfile = mkDefault "${pkgs.fprot}/opt/f-prot/license.key";
 
     environment.systemPackages = [ pkgs.fprot ];
-    environment.etc = singleton {
+    environment.etc."f-prot.conf" = {
       source = "${pkgs.fprot}/opt/f-prot/f-prot.conf";
-      target = "f-prot.conf";
     };
 
-    users.users = singleton
-      { name = fprotUser;
-        uid = config.ids.uids.fprot;
+    users.users.${fprotUser} =
+      { uid = config.ids.uids.fprot;
         description = "F-Prot daemon user";
         home = stateDir;
       };
 
-    users.groups = singleton
-      { name = fprotGroup;
-        gid = config.ids.gids.fprot;
-      };
+    users.groups.${fprotGroup} =
+      { gid = config.ids.gids.fprot; };
 
     services.cron.systemCronJobs = [ "*/${toString cfg.updater.frequency} * * * * root start fprot-updater" ];
 

nixos/modules/services/security/torsocks.nix

@@ -112,10 +112,9 @@ in
   config = mkIf cfg.enable {
     environment.systemPackages = [ pkgs.torsocks (wrapTorsocks "torsocks-faster" cfg.fasterServer) ];
 
-    environment.etc =
-      [ { source = pkgs.writeText "torsocks.conf" (configFile cfg.server);
-          target = "tor/torsocks.conf";
-        }
-      ];
+    environment.etc."tor/torsocks.conf" =
+      {
+        source = pkgs.writeText "torsocks.conf" (configFile cfg.server);
+      };
   };
 }