Update secure coding guidelines project with new path
What does this MR do?
This MR is a continuation of Move secure coding guidelines into GitLab docs gitlab-org/gitlab!25757 (merged) and Add secure coding guidelines to definition of done gitlab-org/gitlab!25672 (merged)
It replaces each file in this project with a note Moved to: https://docs.gitlab.com/ee/development/secure_coding_guidelines.html
Edited by Jerome Z Ng