### Godot version

4.0 Stable

### System information

Ubuntu 22.04

### Issue description

Setting fog_affect_sky = 1 do not have the desired effect when using a Color sky mode. It works properly if we use a procedural sky or the forward+ renderer.

![Screenshot from 2023-03-03 16-50-53](https://user-images.githubusercontent.com/8985409/222870514-0195c4cb-bbca-4e9b-bb6a-6e2a568d2f7b.png)


### Steps to reproduce

Add a sky with a plain color mode like the Clear Color default option. Enable fog and set fog_affect_sky value to 1. Sky is still not affected by fog. 

### Minimal reproduction project
[mobile_fog_sky_bug.zip](https://github.com/godotengine/godot/files/10887265/mobile_fog_sky_bug.zip)


switch (p_params->pass_mode) {
		case PASS_MODE_COLOR: {
			_render_list_template<PASS_MODE_COLOR>(p_draw_list, p_framebuffer_Format, p_params, p_from_element, p_to_element);
		} break;
		case PASS_MODE_COLOR_TRANSPARENT: {
			_render_list_template<PASS_MODE_COLOR_TRANSPARENT>(p_draw_list, p_framebuffer_Format, p_params, p_from_element, p_to_element);
		} break;
		case PASS_MODE_SHADOW: {
			_render_list_template<PASS_MODE_SHADOW>(p_draw_list, p_framebuffer_Format, p_params, p_from_element, p_to_element);
		} break;
		case PASS_MODE_SHADOW_DP: {
			_render_list_template<PASS_MODE_SHADOW_DP>(p_draw_list, p_framebuffer_Format, p_params, p_from_element, p_to_element);
		} break;
		case PASS_MODE_DEPTH_MATERIAL: {
			_render_list_template<PASS_MODE_DEPTH_MATERIAL>(p_draw_list, p_framebuffer_Format, p_params, p_from_element, p_to_element);
		} break;
	}
}
void RenderForwardMobile::_render_list_thread_function(uint32_t p_thread, RenderListParameters *p_params) {