fix: correct case where there could be multiple build containers post-build
fix: correct case where there could be multiple build containers post-build

This happens when we execute several post-release scripts.
alexquick/dokku,dokku/dokku,progrium/dokku,alexquick/dokku,dokku/dokku,jimjag/dokku,claytonbrown/dokku,claytonbrown/dokku,alexquick/dokku,claytonbrown/dokku,alexquick/dokku,claytonbrown/dokku,progrium/dokku,progrium/dokku,alexquick/dokku,jimjag/dokku,dokku/dokku,progrium/dokku,jimjag/dokku,alexquick/dokku,dokku/dokku,claytonbrown/dokku,jimjag/dokku,progrium/dokku,jimjag/dokku,alexquick/dokku,jimjag/dokku,claytonbrown/dokku,dokku/dokku,dokku/dokku,dokku/dokku,jimjag/dokku,jimjag/dokku,alexquick/dokku,progrium/dokku,progrium/dokku,claytonbrown/dokku,claytonbrown/dokku,progrium/dokku,dokku/dokku