icon-library: use gettext from nixpkgs

The vendored gettext fails to build with clang 16 on Darwin. The gettext in nixpkgs works.

pkgs/applications/graphics/icon-library/default.nix

@@ -2,12 +2,14 @@
 , stdenv
 , fetchurl
 , wrapGAppsHook4
+, buildPackages
 , cargo
 , desktop-file-utils
 , meson
 , ninja
 , pkg-config
 , rustc
+, gettext
 , gdk-pixbuf
 , glib
 , gtk4
@@ -25,6 +27,14 @@ stdenv.mkDerivation rec {
     hash = "sha256-nWGTYoSa0/fxnD0Mb2132LkeB1oa/gj/oIXBbI+FDw8=";
   };
 
+  env = lib.optionalAttrs stdenv.isDarwin {
+    # Set the location to gettext to ensure the nixpkgs one on Darwin instead of the vendored one.
+    # The vendored gettext does not build with clang 16.
+    GETTEXT_BIN_DIR = "${lib.getBin buildPackages.gettext}/bin";
+    GETTEXT_INCLUDE_DIR = "${lib.getDev gettext}/include";
+    GETTEXT_LIB_DIR = "${lib.getLib gettext}/lib";
+  };
+
   nativeBuildInputs = [
     cargo
     desktop-file-utils