statix: enable empty_list_concat

Enable statix's empty_list_concat rule and apply its auto-fixes across the affected modules.

modules/programs/i3status.nix

@@ -229,8 +229,7 @@ in
     home.packages = lib.mkIf (cfg.package != null) [ cfg.package ];
 
     xdg.configFile."i3status/config".text = lib.concatStringsSep "\n" (
-      [ ]
-      ++ lib.optional (cfg.general != { }) (formatModule "general" cfg.general)
+      lib.optional (cfg.general != { }) (formatModule "general" cfg.general)
       ++ map formatOrder (sortAttrNamesByPosition lib.lessThan enabledModules)
       ++ lib.mapAttrsToList formatModule (lib.mapAttrs (n: v: v.settings) enabledModules)
     );

modules/programs/matplotlib.nix

@@ -54,8 +54,7 @@ in
   config = mkIf cfg.enable {
     xdg.configFile."matplotlib/matplotlibrc".text =
       lib.concatStringsSep "\n" (
-        [ ]
-        ++ lib.mapAttrsToList (formatLine "") cfg.config
+        lib.mapAttrsToList (formatLine "") cfg.config
         ++ lib.optional (cfg.extraConfig != "") cfg.extraConfig
       )
       + "\n";

modules/programs/zathura.nix

@@ -85,8 +85,7 @@ in
 
     xdg.configFile."zathura/zathurarc".text =
       lib.concatStringsSep "\n" (
-        [ ]
-        ++ lib.optional (cfg.extraConfig != "") cfg.extraConfig
+        lib.optional (cfg.extraConfig != "") cfg.extraConfig
         ++ lib.mapAttrsToList formatLine cfg.options
         ++ lib.mapAttrsToList formatMapLine cfg.mappings
       )

modules/services/vdirsyncer.nix

@@ -11,8 +11,7 @@ let
   cfg = config.services.vdirsyncer;
 
   vdirsyncerOptions =
-    [ ]
-    ++ optional (cfg.verbosity != null) "--verbosity ${cfg.verbosity}"
+    optional (cfg.verbosity != null) "--verbosity ${cfg.verbosity}"
     ++ optional (cfg.configFile != null) "--config ${cfg.configFile}";
 
 in

modules/xresources.nix

@@ -104,8 +104,7 @@ in
     home.file.${cfg.path} = {
       text =
         lib.concatStringsSep "\n" (
-          [ ]
-          ++ lib.optional (cfg.extraConfig != "") cfg.extraConfig
+          lib.optional (cfg.extraConfig != "") cfg.extraConfig
           ++ lib.optionals (cfg.properties != null) (lib.mapAttrsToList formatLine cfg.properties)
         )
         + "\n";

statix.toml

@@ -3,7 +3,6 @@ disabled = [
   "bool_simplification",
   "deprecated_is_null",
   "deprecated_to_path",
-  "empty_list_concat",
   "empty_inherit",
   "empty_let_in",
   "empty_pattern",