### 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)

}
void RenderForwardMobile::_render_particle_collider_heightfield(RID p_fb, const Transform3D &p_cam_transform, const Projection &p_cam_projection, const PagedArray<RenderGeometryInstance *> &p_instances) {
	RENDER_TIMESTAMP("Setup GPUParticlesCollisionHeightField3D");
	RD::get_singleton()->draw_command_begin_label("Render Collider Heightfield");
	_update_render_base_uniform_set();
	RenderSceneDataRD scene_data;
	scene_data.cam_projection = p_cam_projection;
	scene_data.cam_transform = p_cam_transform;
	scene_data.view_projection[0] = p_cam_projection;