fix(artifacts): sort microvm kernel versions by refname

Use refname sorting to always get the latest microvm kernel version,
even if older tags have been updated more recently.

Signed-off-by: James Curtis <jxcurtis@amazon.co.uk>

Author: JamesC1305

resources/rebuild.sh

@@ -111,8 +111,8 @@ function get_tag {
     local KERNEL_VERSION=$1
 
     # list all tags from newest to oldest
-    (git --no-pager tag -l --sort=-creatordate | grep "microvm-kernel-$1\..*\.amzn2" \
-        || git --no-pager tag -l --sort=-creatordate | grep "kernel-$1\..*\.amzn2") | head -n1
+    (git --no-pager tag -l --sort=-v:refname | grep "microvm-kernel-$1\..*\.amzn2" \
+        || git --no-pager tag -l --sort=-v:refname | grep "kernel-$1\..*\.amzn2") | head -n1
 }
 
 function build_al_kernel {