change git command to check for existing hotfix branch

.github/workflows/release-branch.yml

@@ -48,7 +48,8 @@ jobs:
             exit 1
           fi
           branch_name="release/hotfix-${latest_tag}"
-          if git show-ref --quiet refs/heads/$branch_name; then
+          echo ":twisted_rightwards_arrows: branch name: $branch_name"
+          if git rev-parse --verify --quiet "refs/heads/$branch_name" >/dev/null; then
             echo "# :fire: :warning: Hotfix branch already exists: ${branch_name}" >> $GITHUB_STEP_SUMMARY
             exit 0
           fi