Using 3d terrain elevation in a 3rd party basemap style throws javascript error

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**mapbox-gl-js version**: 3.12.0

**browser**: Chrome

### Steps to Trigger Behavior

1. Setup a terrain in your map:
```
map.addSource('mapbox-dem', {
'type': 'raster-dem',
'url': 'mapbox://mapbox.mapbox-terrain-dem-v1',
'tileSize': 512,
'maxzoom': 14
});
// add the DEM source as a terrain layer with exaggerated height
map.setTerrain({ 'source': 'mapbox-dem', 'exaggeration': 1.5 });
```

2. Use a 3rd party basemap style such as USGS or World Topo (see code in demonstration link below)
3. Notice the error in your javascript console `Uncaught TypeError: Cannot read properties of undefined (reading 'get')`

### Link to Demonstration

https://codepen.io/Matt-Palmerlee/pen/NWZrVoJ

### Expected Behavior

The basemap style is changed and elevation is shown without Javascript errors

### Actual Behavior

Elevation seems to display fine, however javascript error is thrown:

```
Uncaught TypeError: Cannot read properties of undefined (reading 'get')
at qs.update (terrain.ts:386:48)
...
```

Perhaps the check on [this line in terrain.ts](https://github.com/mapbox/mapbox-gl-js/blob/main/src/terrain/terrain.ts#L369) should also check style.terrain.properties?

Reproduce the issue with the CodePen example, a raster-dem terrain source, and a third-party basemap style. Inspect src/terrain/terrain.ts around the style.terrain check near line 369 and the failing update code around line 386; done means terrain elevation and style changes work without a JavaScript error.

Written by the indexing model from the issue text.