### 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)


thread_draw_lists.resize(WorkerThreadPool::get_singleton()->get_thread_count());
				RD::get_singleton()->draw_list_switch_to_next_pass_split(thread_draw_lists.size(), thread_draw_lists.ptr());
				render_list_params.subpass = RD::get_singleton()->draw_list_get_current_pass();
				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);
			} else {
				
				RD::DrawListID draw_list = RD::get_singleton()->draw_list_switch_to_next_pass();
				render_list_params.subpass = RD::get_singleton()->draw_list_get_current_pass();
				_render_list(draw_list, fb_format, &render_list_params, 0, render_list_params.element_count);
			}
			RD::get_singleton()->draw_command_end_label(); 
			
			
			if (rb_data.is_valid() && using_subpass_post_process) {
				_post_process_subpass(p_render_data->render_buffers->get_internal_texture(), framebuffer, p_render_data);
			}
			RD::get_singleton()->draw_command_end_label(); 
			RD::get_singleton()->draw_list_end(RD::BARRIER_MASK_ALL_BARRIERS);
		} else {
			RENDER_TIMESTAMP("Render Transparent");
			if (rb_data.is_valid()) {
				framebuffer = rb_data->get_color_fbs(RenderBufferDataForwardMobile::FB_CONFIG_ONE_PASS);
			}
			
			
			RD::FramebufferFormatID fb_format = RD::get_singleton()->framebuffer_get_format(framebuffer);
			RenderListParameters render_list_params(render_list[RENDER_LIST_ALPHA].elements.ptr(), render_list[RENDER_LIST_ALPHA].element_info.ptr(), render_list[RENDER_LIST_ALPHA].elements.size(), reverse_cull, PASS_MODE_COLOR, rp_uniform_set, spec_constant_base_flags, get_debug_draw_mode() == RS::VIEWPORT_DEBUG_DRAW_WIREFRAME, Vector2(), p_render_data->scene_data->lod_distance_multiplier, p_render_data->scene_data->screen_mesh_lod_threshold, p_render_data->scene_data->view_count);
			render_list_params.framebuffer_format = fb_format;