Merge branch '493994-aqualls-random-pile' into 'master'

Security page: update text, remove images

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/169970



Merged-by: Jon Glassman <jglassman@gitlab.com>
Approved-by: Jon Glassman <jglassman@gitlab.com>
Co-authored-by: Amy Qualls <aqualls@gitlab.com>