libindicate-gtk{2,3}: use recent vala

pkgs/development/libraries/libindicate/default.nix

···
 , pkgconfig, autoconf
 , glib, dbus_glib, libdbusmenu-glib
 , gtkVersion, gtk2 ? null, gtk3 ? null
-, pythonPackages, gobjectIntrospection, vala_0_23, gnome_doc_utils
+, pythonPackages, gobjectIntrospection, vala, gnome_doc_utils
 , monoSupport ? false, mono ? null, gtk-sharp-2_0 ? null
  }:
 
···
     sha256 = "10am0ymajx633b33anf6b79j37k61z30v9vaf5f9fwk1x5cw1q21";
   };
 
-  nativeBuildInputs = [ pkgconfig autoconf ];
+  nativeBuildInputs = [ pkgconfig autoconf gobjectIntrospection vala gnome_doc_utils ];
 
   buildInputs = [
     glib dbus_glib libdbusmenu-glib
-    python pygobject2 pygtk gobjectIntrospection vala_0_23 gnome_doc_utils
+    python pygobject2 pygtk
   ] ++ (if gtkVersion == "2"
     then [ gtk2 ] ++ optionals monoSupport [ mono gtk-sharp-2_0 ]
     else [ gtk3 ]);