build(image): always update system package

longhorn/longhorn-8722
longhorn/longhorn-8721

Signed-off-by: Chin-Ya Huang <chin-ya.huang@suse.com>
(cherry picked from commit cdb3017)

package/Dockerfile

@@ -50,6 +50,9 @@ RUN if [ "$TARGETPLATFORM" != "linux/amd64" ] && [ "$TARGETPLATFORM" != "linux/a
     fi
 ENV ARCH ${TARGETPLATFORM#linux/}
 
+RUN zypper -n ref && \
+    zypper update -y
+
 RUN zypper addrepo --refresh https://download.opensuse.org/repositories/system:/snappy/SLE_15/ snappy && \
     zypper --gpg-auto-import-keys ref