add let/in with aliases

modules/system/sops.nix

@@ -1,13 +1,16 @@
 { pkgs, config, lib, inputs, ... }:
 
+let
+  cfg = config.modules.system.sops;
+in
 {
   imports = [ inputs.sops-nix.nixosModules.sops ];
 
-  options = {
-    modules.system.sops.enable = lib.mkEnableOption "enables ssh";
+  options.modules.system.sops = {
+    enable = lib.mkEnableOption "enables sops";
   };
 
-  config = lib.mkIf config.modules.system.sops.enable {
+  config = lib.mkIf cfg.enable {
     # enable and configure sops for secrets
     sops.defaultSopsFile = ../../secrets/secrets.yaml;
     sops.defaultSopsFormat = "yaml";