testing/gnome-shell: disable ppc64le

See f62562e0

testing/gnome-session/APKBUILD

@@ -4,7 +4,7 @@ pkgver=3.32.0
 pkgrel=0
 pkgdesc="GNOME session manager"
 url="https://www.gnome.org/"
-arch="all !aarch64 !armhf !armv7 !s390x"
+arch="all !aarch64 !armhf !armv7 !s390x !ppc64le" # ppc64le limited by mutter
 license="GPL-2.0-or-later"
 depends="gnome-shell polkit alsa-plugins-pulse dconf pulseaudio-alsa"
 makedepends="gnome-settings-daemon-dev libsm-dev