### 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)

#include "render_forward_mobile.h"
#include "core/config/project_settings.h"
#include "core/object/worker_thread_pool.h"
#include "servers/rendering/renderer_rd/storage_rd/light_storage.h"
#include "servers/rendering/renderer_rd/storage_rd/mesh_storage.h"
#include "servers/rendering/renderer_rd/storage_rd/particles_storage.h"
#include "servers/rendering/renderer_rd/storage_rd/texture_storage.h"
#include "servers/rendering/rendering_device.h"
#include "servers/rendering/rendering_server_default.h"
using namespace RendererSceneRenderImplementation;
RendererRD::ForwardID RenderForwardMobile::ForwardIDStorageMobile::allocate_forward_id(RendererRD::ForwardIDType p_type) {
	int32_t index = -1;
	for (uint32_t i = 0; i < forward_id_allocators[p_type].allocations.size(); i++) {
		if (forward_id_allocators[p_type].allocations[i] == false) {
			index = i;
			break;
		}
	}
	if (index == -1) {
		index = forward_id_allocators[p_type].allocations.size();
		forward_id_allocators[p_type].allocations.push_back(true);
		forward_id_allocators[p_type].map.push_back(0xFF);
	} else {
		forward_id_allocators[p_type].allocations[index] = true;
	}
	return index;
}
void RenderForwardMobile::ForwardIDStorageMobile::free_forward_id(RendererRD::ForwardIDType p_type, RendererRD::ForwardID p_id) {