Fix in CreateWorkspace

Previously, the script attempted to directly merge ${merge}, which could f
ail if the branch was not already available locally. This update explicitly
fetches the branch from origin and then merges FETCH_HEAD with --ff, ensuring
the merge works even when the branch is missing locally.

ci-scripts/scripts/create_workspace.sh

@@ -22,5 +22,5 @@ git config user.name "OAI Jenkins"
 git config advice.detachedHead false
 mkdir -p cmake_targets/log
 git checkout -f ${ref}
-[ -n "${merge}" ] && git merge --ff ${merge} -m "Temporary merge for CI"
+[ -n "${merge}" ] && git fetch origin ${merge} && git merge --ff FETCH_HEAD -m "Temporary merge for CI"
 exit 0