### Godot version

4.2.dev 5ee983188de97ae027f9b9c1443438063f708a7e

### System information

Windows 10 - Compatibility renderer 

### Issue description

When running a VR project sky contribution is not working in the compatibility renderer:

![image](https://github.com/godotengine/godot/assets/1945449/7aa19569-95c8-41a2-913b-37b81f4728a7)

It is working fine in normal mode. Can be worked around by setting sky contribution to 0 and providing an ambient color.

### Steps to reproduce

Try any project with a proper sky setup in XR, just switch to compatibility renderer.

### Minimal reproduction project

I'll try and create an MVP soon that can be used without XR hardware, but for now this can be used:
https://github.com/BastiaanOlij/godot_openxr_demo
Lightmap *lightmap = lightmap_owner.get_or_null(p_lightmap);
	ERR_FAIL_NULL(lightmap);
	if (p_points.size()) {
		ERR_FAIL_COND(p_points.size() * 9 != p_point_sh.size());
		ERR_FAIL_COND((p_tetrahedra.size() % 4) != 0);
		ERR_FAIL_COND((p_bsp_tree.size() % 6) != 0);
	}
	lightmap->points = p_points;
	lightmap->point_sh = p_point_sh;
	lightmap->tetrahedra = p_tetrahedra;
	lightmap->bsp_tree = p_bsp_tree;
}
void LightStorage::lightmap_set_baked_exposure_normalization(RID p_lightmap, float p_exposure) {
	Lightmap *lightmap = lightmap_owner.get_or_null(p_lightmap);
	ERR_FAIL_NULL(lightmap);
	lightmap->baked_exposure = p_exposure;
}
PackedVector3Array LightStorage::lightmap_get_probe_capture_points(RID p_lightmap) const {
	Lightmap *lightmap = lightmap_owner.get_or_null(p_lightmap);
	ERR_FAIL_NULL_V(lightmap, PackedVector3Array());
	return lightmap->points;
}
PackedColorArray LightStorage::lightmap_get_probe_capture_sh(RID p_lightmap) const {
	Lightmap *lightmap = lightmap_owner.get_or_null(p_lightmap);
	ERR_FAIL_NULL_V(lightmap, PackedColorArray());
	return lightmap->point_sh;
}
PackedInt32Array LightStorage::lightmap_get_probe_capture_tetrahedra(RID p_lightmap) const {