fix: default to concurrency 1 in gitlab-ci-local
This PR makes concurrency of 1 the default for gitlab-ci-local. It prevents running 6 container builds simultaneously, when not intended. This can be overridden on the cli.
This PR makes concurrency of 1 the default for gitlab-ci-local. It prevents running 6 container builds simultaneously, when not intended. This can be overridden on the cli.