Change return logic in pipelines_controller

What does this MR do?

This changes the logic from the pipelines controller to return the controller action early and prevent from the queries from executing, that causes a timeout currently due to the queries not being optimized The original MR where this feature flag was introduced

!48267 (merged)

The rollout issue

#290153 (closed)

Screenshots (strongly suggested)

N/A

Does this MR meet the acceptance criteria?

Conformity

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