Override max size limits for the gitlab-docs-archives project

Similar to https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/9019, we'd like to change the quota for artifacts, Pages, and repository sizes to 15GB.

We want to deploy multiple docs versions, and from a calculation, we're currently at 12.8GB. See gitlab-org/gitlab-docs-archives!4 (merged).

• As an admin, go to https://gitlab.com/gitlab-org/gitlab-docs-archives/pages and update the maximum Pages size to 15000.
• As an admin, go to https://gitlab.com/gitlab-org/gitlab-docs-archives/-/settings/ci_cd in General pipelines and update the maximum artifacts size to 15000.
• As an admin, go to https://gitlab.com/gitlab-org/gitlab-docs-archives/edit and update the Repository size limit to 15000. No need to actually change this, since the Docker image is compressed a lot, see https://gitlab.com/gitlab-com/gl-infra/reliability/-/issues/16811#note_1171756906

PS. The issue says created 1 month ago, but this is just because I moved it from gitlab-org/gitlab-docs-archives#4 (moved).