Fix empty state problem for pipeline schedules refactor

What does this MR do and why?

When testing the rollout of pipeline_schedules_vue on a personal project. I found that when navigating to tabs that did not have data the empty state was shown. This MR fixes that issue to only show empty state when on the default tab scope.

Related epic: &6189 (closed)

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. In rails console enable the experiment fully

   Feature.enable(:pipeline_schedules_vue)

2. Visit project with pipeline schedules (have one active and not inactive)
3. Ensure empty state does not show on inactive tab
4. Visit blank project, ensure empty state shows when visiting the schedules

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.