Merge branch 'remove-sec-arch-template' into 'master'

Remove Sec Architectural Council template

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/171215



Merged-by: Lucas Charles <me@lucascharles.me>
Approved-by: Lucas Charles <me@lucascharles.me>
Co-authored-by: Thiago Figueiró <tfigueiro@gitlab.com>