### 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)


if ((uint32_t)render_list_params.element_count > render_list_thread_threshold && false) {
				
				
				thread_draw_lists.resize(WorkerThreadPool::get_singleton()->get_thread_count());
				RD::get_singleton()->draw_list_begin_split(framebuffer, thread_draw_lists.size(), thread_draw_lists.ptr(), can_continue_color ? RD::INITIAL_ACTION_CONTINUE : RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ, can_continue_depth ? RD::INITIAL_ACTION_CONTINUE : RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ);
				WorkerThreadPool::GroupID group_task = WorkerThreadPool::get_singleton()->add_template_group_task(this, &RenderForwardMobile::_render_list_thread_function, &render_list_params, thread_draw_lists.size(), -1, true, SNAME("ForwardMobileRenderSubpass"));
				WorkerThreadPool::get_singleton()->wait_for_group_task_completion(group_task);
				RD::get_singleton()->draw_list_end(RD::BARRIER_MASK_ALL_BARRIERS);
			} else {
				
				RD::DrawListID draw_list = RD::get_singleton()->draw_list_begin(framebuffer, can_continue_color ? RD::INITIAL_ACTION_CONTINUE : RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ, can_continue_depth ? RD::INITIAL_ACTION_CONTINUE : RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ);
				_render_list(draw_list, fb_format, &render_list_params, 0, render_list_params.element_count);
				RD::get_singleton()->draw_list_end(RD::BARRIER_MASK_ALL_BARRIERS);
			}
			RD::get_singleton()->draw_command_end_label(); 
		}
	}
	if (rb_data.is_valid() && !using_subpass_post_process) {
		RD::get_singleton()->draw_command_begin_label("Post process pass");
		
		RENDER_TIMESTAMP("Tonemap");
		_render_buffers_post_process_and_tonemap(p_render_data);
		RD::get_singleton()->draw_command_end_label(); 
	}
	if (rb_data.is_valid()) {
		_disable_clear_request(p_render_data);
	}
	_render_buffers_debug_draw(p_render_data);
}
void RenderForwardMobile::_render_shadow_pass(RID p_light, RID p_shadow_atlas, int p_pass, const PagedArray<RenderGeometryInstance *> &p_instances, const Plane &p_camera_plane, float p_lod_distance_multiplier, float p_screen_mesh_lod_threshold, bool p_open_pass, bool p_close_pass, bool p_clear_region, RenderingMethod::RenderInfo *p_render_info) {