### Godot version

4.1.1

### System information

windows 11, mobile renderer

### Issue description

On Mobile Vulkan renderer, the clear color is 50% lighter than expected

See steps to reproduce and Minimal reproduction project below.

The box and background have the same color on Forward+ and compatibility, but not on Mobile
happens also in runtime on exported project, not only in editor preview

Images of the same scene from
compatibility:
![compatibility](https://github.com/godotengine/godot/assets/11915378/a874fa86-c16f-43ef-aed7-c2066b770ac1)
Forward+:
![forward](https://github.com/godotengine/godot/assets/11915378/e416f9a6-dfd4-4c47-bbc2-b552ca58f83c)
Mobile:
![mobile](https://github.com/godotengine/godot/assets/11915378/e28e2db8-f7c3-47e2-8c0a-44ce937c9270)


### Steps to reproduce

 - add a CSGBox3D with "unshaded" shading, and albedo of #545454
 - add environment with Background = Custom color and color of #545454

Box and background are not the same color

### Minimal reproduction project

[bg_color.zip](https://github.com/godotengine/godot/files/12174822/bg_color.zip)

for (const int &index : p_render_data->cube_shadows) {
			_render_shadow_pass(p_render_data->render_shadows[index].light, p_render_data->shadow_atlas, p_render_data->render_shadows[index].pass, p_render_data->render_shadows[index].instances, camera_plane, lod_distance_multiplier, p_render_data->scene_data->screen_mesh_lod_threshold, true, true, true, p_render_data->render_info);
		}
		if (p_render_data->directional_shadows.size()) {
			
			light_storage->update_directional_shadow_atlas();
			RD::get_singleton()->draw_list_begin(light_storage->direction_shadow_get_fb(), RD::INITIAL_ACTION_DROP, RD::FINAL_ACTION_DISCARD, RD::INITIAL_ACTION_CLEAR, RD::FINAL_ACTION_CONTINUE);
			RD::get_singleton()->draw_list_end();
		}
	}
	bool render_shadows = p_render_data->directional_shadows.size() || p_render_data->shadows.size();
	
	if (render_shadows) {
		RENDER_TIMESTAMP("Render Shadows");
		_render_shadow_begin();
		
		for (uint32_t i = 0; i < p_render_data->directional_shadows.size(); i++) {
			_render_shadow_pass(p_render_data->render_shadows[p_render_data->directional_shadows[i]].light, p_render_data->shadow_atlas, p_render_data->render_shadows[p_render_data->directional_shadows[i]].pass, p_render_data->render_shadows[p_render_data->directional_shadows[i]].instances, camera_plane, lod_distance_multiplier, p_render_data->scene_data->screen_mesh_lod_threshold, false, i == p_render_data->directional_shadows.size() - 1, false, p_render_data->render_info);
		}
		
		for (uint32_t i = 0; i < p_render_data->shadows.size(); i++) {
			_render_shadow_pass(p_render_data->render_shadows[p_render_data->shadows[i]].light, p_render_data->shadow_atlas, p_render_data->render_shadows[p_render_data->shadows[i]].pass, p_render_data->render_shadows[p_render_data->shadows[i]].instances, camera_plane, lod_distance_multiplier, p_render_data->scene_data->screen_mesh_lod_threshold, i == 0, i == p_render_data->shadows.size() - 1, true, p_render_data->render_info);
		}
		_render_shadow_process();
		_render_shadow_end(RD::BARRIER_MASK_NO_BARRIER);
	}
	
	RD::get_singleton()->barrier(RD::BARRIER_MASK_ALL_BARRIERS, RD::BARRIER_MASK_ALL_BARRIERS);
	bool using_shadows = true;
	if (p_render_data->reflection_probe.is_valid()) {