Exclude work items from archived projects by default

What does this MR do and why?

This MR excludes work items from archived projects from being returned from the namespace.workItems GQL endpoints, mimicking the behaviour of the legacy issues queries.

References

• #573145 (closed)
• https://gitlab.slack.com/archives/C02403NRD40/p1759292839695799

Screenshots or screen recordings

See the first item listed in before block is from archived project!

Before	After

How to set up and validate locally

1. Enable the work_items_group_issues_list feature flag
2. Create a new group Parent Group, and 2 projects A and B inside that group
3. Create an issue in both project A and B
4. Navigate to the Parent Group > Issues page. Notice both issues are displayed
5. Archive project A (via ⋮ > Project Settings > Advanced > Archive)
6. Navigate back to the Parent Group > Issues page. Notice only the issue in project B is displayed

MR acceptance checklist

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Related to #573145 (closed)