Display issue of ground-sticking geojson in useWebVR mode

### What happened?

When useWebVR is set to true and **there is terrain relief**, the ground-fitting geojson is not fully displayed on the left screen

### Reproduction steps

1.let source = await Cesium.GeoJsonDataSource.load(
'http://localhost:5000/data.json'
, { clampToGround: true });
viewer.flyTo(source);
2.viewer.useWebVR = true;

### Sandcastle example

`import * as Cesium from "cesium";
import Sandcastle from "Sandcastle";

const viewer = new Cesium.Viewer("cesiumContainer", {
skyAtmosphere: false,
shouldAnimate: true,
terrain: Cesium.Terrain.fromWorldTerrain(),
scene3DOnly: true,
});

//Example 2: Load with basic styling options.
Sandcastle.addToolbarButton("Basic styling", function () {
viewer.dataSources.add(
Cesium.GeoJsonDataSource.load(
"../../SampleData/ne_10m_us_states.topojson",
{
stroke: Cesium.Color.HOTPINK,
fill: Cesium.Color.PINK.withAlpha(0.5),
strokeWidth: 3,
clampToGround: true
},
),
);
});

viewer.dataSources.removeAll();

//Set the camera to a US centered tilted view and switch back to moving in world coordinates.
viewer.camera.lookAt(
Cesium.Cartesian3.fromDegrees(-98.0, 40.0),
new Cesium.Cartesian3(0.0, -4790000.0, 3930000.0),
);
viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY);
viewer.scene.useWebVR = true;
`

### Environment

Browser: Microsoft Edge 版本 119.0.2151.72 (正式版本) (64 位)
CesiumJS Version:1.134
Operating System:window 11

Start with the provided Sandcastle example and reproduce the issue with terrain, clampToGround GeoJSON, and viewer.scene.useWebVR enabled. Compare the left and right screens while checking the WebVR rendering path; done means the ground-fitting GeoJSON is fully displayed on both screens over terrain.

Written by the indexing model from the issue text.