www/gitlab: security and bugfix update to 18.3.5
Changes: https://about.gitlab.com/releases/2025/10/22/patch-release-gitlab-18-5-1-released/
Security: f741ea93-af61-11f0-98b5-2cf05da270f3
(cherry picked from commit 9b4801f0c224430f80963f81f4e2c1db511909d8)