Fix branch deletion being not detected

Author: AB-xdev

.github/workflows/update-from-template.yml

@@ -210,7 +210,7 @@ jobs:
 
             echo "Checking if update-branch-merged exists"
             git fetch
-            if [[ $(git rev-parse origin/${{ env.UPDATE_BRANCH_MERGED }}) ]]; then
+            if [[ $(git ls-remote --heads origin refs/heads/${{ env.UPDATE_BRANCH_MERGED }}) ]]; then
               echo "Branch still exists; Continuing..."
             else
               echo "Branch origin/${{ env.UPDATE_BRANCH_MERGED }} is missing"