ci/prepare_environment: fail in case of error

Signed-off-by: Unai Martinez-Corral <umartinezcorral@antmicro.com>

.github/scripts/prepare_environment.sh

@@ -16,6 +16,8 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
+set -e
+
 echo '::group::Install dependencies'
 sudo apt update -y
 sudo apt install -y git wget xz-utils