Add Security/SAST-IaC.latest.gitlab-ci.yml template

What does this MR do and why?

This adds the vendored template for IaC SAST under /lib/gitlab/ci/templates/Security. The template just includes the corresponding template in /lib/gitlab/ci/templates/Jobs.

This MR is dependent on !73074 (merged), which adds the /lib/gitlab/ci/templates/Jobs template.

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)