www/gitlab: security and patch update to 18.0.2

Changes: https://about.gitlab.com/releases/2025/06/11/patch-release-gitlab-18-0-2-released/

Security: ae028662-475e-11f0-9ca4-2cf05da270f3
(cherry picked from commit 5874ca4139397aca47ab80f982c7b1ca6d4da21a)