Add spec for multiple quarantine projects

What does this MR do?

Add specs for quarantining a test in multiple pipeline projects using (for example) quarantine: { only: { pipeline: [:staging, :canary, :production] } }

Note: This is an existing functionality. This MR only adds specs so that the functionality is documented in tests as well.

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• [-] Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content