Set early exit options in shell scripts for tofu upgrades

.gitlab/scripts/renovate-post-upgrade.sh

 #!/usr/bin/env sh
 
+set -e
+
 # This script is just used to add the `latest_version` to the
 # list of supported versions because natively that is
 # cumbersome to achieve.

.gitlab/scripts/update-opentofu-versions.sh

 #!/usr/bin/env sh
 
+set -e
+
 echo "Updating template files ..."
 
 templates="templates/apply.yml templates/custom-command.yml templates/destroy.yml templates/fmt.yml templates/full-pipeline.yml templates/job-templates.yml templates/plan.yml templates/test.yml templates/validate-plan-apply.yml templates/validate-plan-destroy.yml templates/validate-plan.yml templates/validate.yml"