firefox: do not define gtk_modules in darwin (#454842)

        ++ lib.optional smartcardSupport opensc

        ++ pkcs11Modules

        ++ lib.optionals (!isDarwin) gtk_modules;

      gtk_modules = [ libcanberra-gtk3 ];

      gtk_modules = lib.optionals (!isDarwin) [ libcanberra-gtk3 ];

      # Darwin does not rename bundled binaries

      launcherName = "${applicationName}${lib.optionalString (!isDarwin) nameSuffix}";