ci: try to resolve network issues

.ci/sync-latest.sh

@@ -19,12 +19,7 @@ rm -rf "${oci_dir}" ; mkdir "${oci_dir}"
 r=0
 
 img_copy() {
-    for i in $(seq 1 3) ; do
-        if skopeo copy --all "$@" ; then
-            return 0
-        fi
-    done
-    return 1
+    skopeo copy --retry 7 --retry-delay 60s --all "$@"
 }
 
 while : ; do