Recommend against adding jobs requiring authentication to CI components

What does this MR do and why?

This merge request recommends against adding jobs to CI components that may require authentication as they may not work when mirrored on self-managed instances where unauthorized access is not allowed.

The recommendation came up as a result of an issue with certain jobs for the following components:

• https://gitlab.com/components/secret-detection
• https://gitlab.com/components/sast
• https://gitlab.com/components/code-quality
• https://gitlab.com/components/container-scanning

Please see this thread for more information.

MR acceptance checklist

I have evaluated this MR against the MR acceptance checklist.