CI: update KAS container to 4.7

Bump the KAS container to the latest version

Signed-off-by: Jon Mason <jon.mason@arm.com>

.gitlab-ci.yml

@@ -1,4 +1,4 @@
-image: ${MIRROR_GHCR}/siemens/kas/kas:4.4
+image: ${MIRROR_GHCR}/siemens/kas/kas:4.7
 
 variables:
   # These are needed as the k8s executor doesn't respect the container