nix: exorcise all with <expr>; uses

services/media.nix

@@ -1,11 +1,17 @@
 { config, lib, ... }:
 let
-  mediaServices = with config.my.services; [
-    jellyfin
-    transmission
-  ];
+  inherit (lib)
+    mkIf
+  ;
+
+  mediaServices = builtins.attrValues {
+    inherit (config.my.services)
+      jellyfin
+      transmission
+    ;
+  };
   needed = builtins.any (service: service.enable) mediaServices;
 in
 {
-  config.users.groups.media = lib.mkIf needed { };
+  config.users.groups.media = mkIf needed { };
 }