### 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
return _get_directional_shadow_rect(directional_shadow.size, directional_shadow.light_count, directional_shadow.current_light);
}
int LightStorage::get_directional_light_shadow_size(RID p_light_instance) {
	ERR_FAIL_COND_V(directional_shadow.light_count == 0, 0);
	Rect2i r = _get_directional_shadow_rect(directional_shadow.size, directional_shadow.light_count, 0);
	LightInstance *light_instance = light_instance_owner.get_or_null(p_light_instance);
	ERR_FAIL_NULL_V(light_instance, 0);
	switch (light_directional_get_shadow_mode(light_instance->light)) {
		case RS::LIGHT_DIRECTIONAL_SHADOW_ORTHOGONAL:
			break; 
		case RS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_2_SPLITS:
			r.size.height /= 2;
			break;
		case RS::LIGHT_DIRECTIONAL_SHADOW_PARALLEL_4_SPLITS:
			r.size /= 2;
			break;
	}
	return MAX(r.size.width, r.size.height);
}
#endif