Add Jobs/SAST-IaC.latest.gitlab-ci.yml vendored template

What does this MR do and why?

This adds the vendored template for IaC SAST under /lib/gitlab/ci/templates/Jobs. It includes a reference to the yet-to-be-released image for kics.

There may be overlap between kics and kubesec analyzers, but this template does not attempt to deal with that, yet. We may do so in a future iteration.

How to set up and validate locally

I opened an MR in a test project to verify the template content: rossfuhrman/kics-testing!6

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #343820 (closed)