### 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)

RendererRD::LightStorage *light_storage = RendererRD::LightStorage::get_singleton();
	ERR_FAIL_COND(!light_storage->owns_light_instance(p_light));
	RID base = light_storage->light_instance_get_base_light(p_light);
	Rect2i atlas_rect;
	uint32_t atlas_size = 1;
	RID atlas_fb;
	bool using_dual_paraboloid = false;
	bool using_dual_paraboloid_flip = false;
	Vector2i dual_paraboloid_offset;
	RID render_fb;
	RID render_texture;
	float zfar;
	bool use_pancake = false;
	bool render_cubemap = false;
	bool finalize_cubemap = false;
	bool flip_y = false;
	Projection light_projection;
	Transform3D light_transform;
	if (light_storage->light_get_type(base) == RS::LIGHT_DIRECTIONAL) {