Merge branch 'rd/sast-remove-unwanted-content' into 'master'

Remove outdated content from the SAST docs page

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/127571



Merged-by: Lorena Ciutacu <lciutacu@gitlab.com>
Approved-by: Lorena Ciutacu <lciutacu@gitlab.com>
Co-authored-by: Russell Dickenson <rdickenson@gitlab.com>