www/gitlab: major update to 18.5.1
Changes: https://about.gitlab.com/releases/2025/10/16/gitlab-18-5-released/
Changes: https://about.gitlab.com/releases/2025/10/22/patch-release-gitlab-18-5-1-released/
(cherry picked from commit 3cb9bb1e74aba976577c366e7d22832c4de107e8)