Packer: default to RHEL-9.3 Schutzfile config for rhel-9

This is necessary to get the proper osbuild SHA to install the latest
required osbuild version into the image.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

tools/appsre-build-worker-packer.sh

@@ -57,7 +57,7 @@ EOF
         # get distro name for schutzfile
         local schutzfile_distro="$distro"
         if [[ $schutzfile_distro == rhel-9 ]]; then
-            schutzfile_distro=rhel-9.0
+            schutzfile_distro=rhel-9.3
         fi
 
         # get osbuild_commit from schutzfile