pipewire: fix cross to executable host

ffado uses wrapQtAppsHook in nativeBuildInputs, but and wrapQtAppsHook
depends on qtsvg, but buildPackages.qt5.qtsvg doesn't build when cross
compiling.  So even in the canExecute case, we can't do this.

Link: #269756

pkgs/development/libraries/pipewire/default.nix

@@ -66,7 +66,7 @@
 , xorg
 , mysofaSupport ? true
 , libmysofa
-, ffadoSupport ? x11Support && stdenv.buildPlatform.canExecute stdenv.hostPlatform
+, ffadoSupport ? x11Support && lib.systems.equals stdenv.buildPlatform stdenv.hostPlatform
 , ffado
 , libselinux
 }: