Add Deprecation Notice: dast_api_timeout_default_value change

upstream mr title: Add Deprecation Notice: dast_api_timeout_default_value change

upstream mr link: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/180461

upstream mr target branch: master

upstream mr milestone: 17.9

upstream mr merged at: 2025-02-15 04:41:17 +0800