Globe translucency not impacting polylines

### What happened?

Hello!
When setting those options:

```ts
viewer.scene.globe.depthTestAgainstTerrain = true;
viewer.scene.globe.translucency.enabled = true;
viewer.scene.globe.translucency.backFaceAlpha = 1;
viewer.scene.globe.translucency.frontFaceAlpha = 0.9999;
```

The polylines are almost not opacified. It seems like when translucency.enabled is set to true and frontFaceAlpha different from 1, the polylines are always visible as if they where above terrain (but we should barely see them).

### Reproduction steps

1.Display polylines above and under globe
2. Display terrain
3. Set viewer.scene.globe.depthTestAgainstTerrain to true
3. Set viewer.scene.globe.translucency.enabled to true
4. Set viewer.scene.globe.translucency.frontFaceAlpha to 0.9999
...

### Sandcastle example

https://sandcastle.cesium.com/#c=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

### Environment

Browser: Edge 148.0.3967.96
CesiumJS Version: Cesium 1.142.0
Operating System: Windows 11

### AI acknowledgment

- [ ] I used AI to generate this issue report.
- [ ] (If the above is checked) I have reviewed the AI-generated content before submitting.

Start with the linked Sandcastle example and reproduce the issue using Globe translucency, depthTestAgainstTerrain, and polylines. Trace the globe translucency and polyline rendering entry points to determine why frontFaceAlpha 0.9999 does not opacify terrain-hidden lines. Done means polylines under the globe are barely visible while lines above terrain remain visible, with the relevant rendering tests passing if available.

Written by the indexing model from the issue text.