clanModules/state-version: use default of vars

clanModules/state-version/default.nix

@@ -3,19 +3,16 @@ let
   var = config.clan.core.vars.generators.state-version.files.version or { };
 in
 {
-  config = lib.mkMerge [
-    (lib.mkIf ((var.value or null) != null) {
   system.stateVersion = lib.mkDefault var.value;
-    })
 
-    {
   clan.core.vars.generators.state-version = {
-        files.version.secret = false;
+    files.version = {
+      secret = false;
+      value = lib.mkDefault lib.version;
+    };
     runtimeInputs = [ ];
     script = ''
       echo -n ${lib.versions.majorMinor config.system.stateVersion} > $out/version
     '';
   };
 }
-  ];
-}