Texture preview Slice slider is not greyed out when 2D Array has only one slice and no interaction is available

Steps to reproduce:

1. Create a new URP project
2. Import the attached texture (or any other texture) and select it
3. Change Texture Shape to "2D Array"
4. Click Apply
5. Observe the Slice slider in the Texture preview

Actual results: Slider renders in its normal enabled state but cannot be dragged and creates confusing UX

Expected results: Slice slider is greyed out / disabled when there's only one slice to display and no functionality is available

Reproducible with versions: 6000.0.0f1, 6000.3.16f1, 6000.4.9f1, 6000.5.0b10, 6000.6.0a6

Tested on (OS): Ubuntu 24.04, macOS 26.4

Notes:

• Other sliders are correctly removed or greyed out when they have no functionality