USD lights are not visible in Maya Render Setup

USD lights disappears from the viewport when user switch to a render setup that is not the master layer. The lights still renders in the RenderView in its individual layer.

**Steps to reproduce the behavior:**

1. Load the lights in the USD stage. Then in the render setup, create a layer along with a collection, add the lights and a simple sphere in the collection. Switch to the layer. The lights will disappear.
2. Now start a Render preview, the lights should still render.

**Expected behavior**
User will want to check the light directions in viewport, so it is important that the lights are visible not just in the render but also the viewport.

**Attachments**
https://github.com/user-attachments/assets/c73d1199-310f-4c6e-8569-e229fbb365b6

**Specs :**
- Windows 11
- MayaUSD 0.32
- Maya 2026.1