### 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
ShadowAtlas *shadow_atlas = shadow_atlas_owner.get_or_null(p_atlas);
	ERR_FAIL_NULL_V(shadow_atlas, false);
	LightInstance *li = light_instance_owner.get_or_null(p_light_instance);
	ERR_FAIL_NULL_V(li, false);
	if (shadow_atlas->size == 0 || shadow_atlas->smallest_subdiv == 0) {
		return false;
	}
	uint32_t quad_size = shadow_atlas->size >> 1;
	int desired_fit = MIN(quad_size / shadow_atlas->smallest_subdiv, next_power_of_2(quad_size * p_coverage));
	int valid_quadrants[4];
	int valid_quadrant_count = 0;
	int best_size = -1; 
	int best_subdiv = -1; 
	
	for (int i = 0; i < 4; i++) {
		int q = shadow_atlas->size_order[i];
		int sd = shadow_atlas->quadrants[q].subdivision;
		if (sd == 0) {
			continue; 
		}
		int max_fit = quad_size / sd;