[librsvg-oci-images] Add xz to the openSUSE packages

[Federico Mena Quintero <federico src gnome org>]

commit 38f0d9eda7237529e4aff2abefc28860846c05c8
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Sep 2 17:36:34 2019 -0500

    Add xz to the openSUSE packages

 opensuse/prepare.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/opensuse/prepare.sh b/opensuse/prepare.sh
index fc8855d..acf8b8c 100644
--- a/opensuse/prepare.sh
+++ b/opensuse/prepare.sh
@@ -5,4 +5,5 @@ zypper install -y gcc rust rust-std cargo make vala \
     automake autoconf libtool gettext itstool git \
     gtk-doc gobject-introspection-devel gtk3-devel \
     libxml2-devel libcroco-devel cairo-devel \
-    pango-devel gdk-pixbuf-devel ccache gettext-tools
+    pango-devel gdk-pixbuf-devel ccache gettext-tools \
+    xz