### 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
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_BASE_LEVEL, 0);
			glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAX_LEVEL, sky->mipmap_count - 1);
			glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
			GLES3::Utilities::get_singleton()->texture_allocated_data(sky->raw_radiance, Image::get_image_data_size(sky->radiance_size, sky->radiance_size, Image::FORMAT_RGBA8, true), "Sky raw radiance map");
		}
		sky->reflection_dirty = true;
		sky->processing_layer = 0;
		Sky *next = sky->dirty_list;
		sky->dirty_list = nullptr;
		sky->dirty = false;
		sky = next;
	}
	dirty_sky_list = nullptr;
}
void RasterizerSceneGLES3::_setup_sky(const RenderDataGLES3 *p_render_data, const PagedArray<RID> &p_lights, const Projection &p_projection, const Transform3D &p_transform, const Size2i p_screen_size) {
	GLES3::LightStorage *light_storage = GLES3::LightStorage::get_singleton();
	GLES3::MaterialStorage *material_storage = GLES3::MaterialStorage::get_singleton();
	ERR_FAIL_COND(p_render_data->environment.is_null());
	GLES3::SkyMaterialData *material = nullptr;
	Sky *sky = sky_owner.get_or_null(environment_get_sky(p_render_data->environment));
	RID sky_material;
	GLES3::SkyShaderData *shader_data = nullptr;
	if (sky) {
		sky_material = sky->material;
		if (sky_material.is_valid()) {
			material = static_cast<GLES3::SkyMaterialData *>(material_storage->material_get_data(sky_material, RS::SHADER_SKY));
			if (!material || !material->shader_data->valid) {
				material = nullptr;
			}
		}