modularizer: Remove default modules option.

modularizer.nix

···
       description = "List of paths to import";
     };
 
-    enableDefaultModules = lib.mkOption {
-      type = lib.types.bool;
-      default = true;
-      description = "Enable default modules";
-    };
-
     modules = lib.mkOption {
       # ./path/name/type.nix or ./path/name/type/default.nix
       # --> becomes -->
···
       in finalize;
     };
 
-  };
-
-  config.modularizer = {
-    paths =
-    let
-      path = self + "/modules";
-    in lib.mkIf (cfg.enableDefaultModules && builtins.pathExists path) [ path ];
   };
 }