Get verbose logging from the branch script. (#2281)

.github/scripts/get-or-create-release-branch.sh

@@ -3,7 +3,7 @@
 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 #
-set -e
+set -eux
 
 # Compute the name of the release branch starting from the version that needs to be released ($SEMANTIC_VERSION).
 # If it's the beginning of a new release series, the branch is created and pushed to the remote (chosen according to