www/gitlab: security and bugfix update to 18.5.2

With the upgrade of node from 22 to 24 I see the need of more memory
for the asset compilation.
Plan to provide one more GB memory to your gitlab instance.

Changes: https://about.gitlab.com/releases/2025/11/12/patch-release-gitlab-18-5-2-released/
Security: 5a1d6309-c04a-11f0-85d8-2cf05da270f3