Remove the --build flag from babuctl.sh

Description

The artifacts ought to be build with a pipeline, not locally. In addition, this flag doesn't really work anyway. Having the flag available in misleading. Additional libraries - go, python, etc are needed for the build to work, plus you need to clone the repo, and you want to specify the tag for the image you build. It's misleading to have this option available. We've been building images locally, we've been using commands directly in the repos. We've never tried to use this flag.

Doing this would involve deleting the function, deleting the flag processing in the input function, and removing the reference from the help function.

Acceptance Criteria

• Flag function from babuctl.sh removed
• Flag processing in the input function removed
• Reference from the help function removed