### 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
glBindBuffer(GL_UNIFORM_BUFFER, sky_globals.directional_light_buffer);
		GLES3::Utilities::get_singleton()->buffer_allocate_data(GL_UNIFORM_BUFFER, sky_globals.directional_light_buffer, directional_light_buffer_size, nullptr, GL_STREAM_DRAW, "Sky DirectionalLight UBO");
		glBindBuffer(GL_UNIFORM_BUFFER, 0);
	}
	{
		String global_defines;
		global_defines += "#define MAX_GLOBAL_SHADER_UNIFORMS 256\n"; 
		global_defines += "\n#define MAX_LIGHT_DATA_STRUCTS " + itos(config->max_renderable_lights) + "\n";
		global_defines += "\n#define MAX_DIRECTIONAL_LIGHT_DATA_STRUCTS " + itos(MAX_DIRECTIONAL_LIGHTS) + "\n";
		global_defines += "\n#define MAX_FORWARD_LIGHTS " + itos(config->max_lights_per_object) + "u\n";
		material_storage->shaders.scene_shader.initialize(global_defines);
		scene_globals.shader_default_version = material_storage->shaders.scene_shader.version_create();
		material_storage->shaders.scene_shader.version_bind_shader(scene_globals.shader_default_version, SceneShaderGLES3::MODE_COLOR);
	}
	{
		
		scene_globals.default_shader = material_storage->shader_allocate();
		material_storage->shader_initialize(scene_globals.default_shader);
		material_storage->shader_set_code(scene_globals.default_shader, R"(
// Default 3D material shader.
shader_type spatial;
void vertex() {
	ROUGHNESS = 0.8;
}
void fragment() {
	ALBEDO = vec3(0.6);
	ROUGHNESS = 0.8;
	METALLIC = 0.2;
}
)");