Expand project CI lint API specs

What does this MR do?

Test guest access to project CI lint API endpoint.

Related #29568 (closed). Followup from !42998 (merged)

Does this MR meet the acceptance criteria?

Conformity

• N/A Changelog entry
• N/A Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• N/A Database guides
• N/A Separation of EE specific content