### 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
if (is_using_physical_light_units()) {
			energy *= light_storage->light_get_param(base, RS::LIGHT_PARAM_INTENSITY);
			
			if (type == RS::LIGHT_OMNI) {
				energy *= 1.0 / (Math_PI * 4.0);
			} else {
				
				
				energy *= 1.0 / Math_PI;
			}
		} else {
			energy *= Math_PI;
		}
		if (p_render_data->camera_attributes.is_valid()) {
			energy *= RSG::camera_attributes->camera_attributes_get_exposure_normalization_factor(p_render_data->camera_attributes);
		}
		light_data.color[0] = linear_col.r * energy;
		light_data.color[1] = linear_col.g * energy;
		light_data.color[2] = linear_col.b * energy;
		light_data.attenuation = light_storage->light_get_param(base, RS::LIGHT_PARAM_ATTENUATION);
		light_data.inv_spot_attenuation = 1.0f / light_storage->light_get_param(base, RS::LIGHT_PARAM_SPOT_ATTENUATION);
		float spot_angle = light_storage->light_get_param(base, RS::LIGHT_PARAM_SPOT_ANGLE);
		light_data.cos_spot_angle = Math::cos(Math::deg_to_rad(spot_angle));
		light_data.specular_amount = light_storage->light_get_param(base, RS::LIGHT_PARAM_SPECULAR) * 2.0;
		
		const bool needs_shadow =
				p_using_shadows &&
				light_storage->owns_shadow_atlas(p_render_data->shadow_atlas) &&
				light_storage->shadow_atlas_owns_light_instance(p_render_data->shadow_atlas, li->self) &&
				light_storage->light_has_shadow(base);