### 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)

atlas_rect_norm.position /= directional_shadow_size;
		atlas_rect_norm.size /= directional_shadow_size;
		light_storage->light_instance_set_directional_shadow_atlas_rect(p_light, p_pass, atlas_rect_norm);
		zfar = RSG::light_storage->light_get_param(base, RS::LIGHT_PARAM_RANGE);
		render_fb = light_storage->direction_shadow_get_fb();
		render_texture = RID();
		flip_y = true;
	} else {
		
		ERR_FAIL_COND(!light_storage->owns_shadow_atlas(p_shadow_atlas));
		ERR_FAIL_COND(!light_storage->shadow_atlas_owns_light_instance(p_shadow_atlas, p_light));
		RSG::light_storage->shadow_atlas_update(p_shadow_atlas);
		uint32_t key = light_storage->shadow_atlas_get_light_instance_key(p_shadow_atlas, p_light);
		uint32_t quadrant = (key >> RendererRD::LightStorage::QUADRANT_SHIFT) & 0x3;
		uint32_t shadow = key & RendererRD::LightStorage::SHADOW_INDEX_MASK;
		uint32_t subdivision = light_storage->shadow_atlas_get_quadrant_subdivision(p_shadow_atlas, quadrant);
		ERR_FAIL_INDEX((int)shadow, light_storage->shadow_atlas_get_quadrant_shadow_size(p_shadow_atlas, quadrant));
		uint32_t shadow_atlas_size = light_storage->shadow_atlas_get_size(p_shadow_atlas);
		uint32_t quadrant_size = shadow_atlas_size >> 1;
		atlas_rect.position.x = (quadrant & 1) * quadrant_size;
		atlas_rect.position.y = (quadrant >> 1) * quadrant_size;
		uint32_t shadow_size = (quadrant_size / subdivision);
		atlas_rect.position.x += (shadow % subdivision) * shadow_size;
		atlas_rect.position.y += (shadow / subdivision) * shadow_size;
		atlas_rect.size.width = shadow_size;
		atlas_rect.size.height = shadow_size;
		zfar = light_storage->light_get_param(base, RS::LIGHT_PARAM_RANGE);
		if (light_storage->light_get_type(base) == RS::LIGHT_OMNI) {
			bool wrap = (shadow + 1) % subdivision == 0;
			dual_paraboloid_offset = wrap ? Vector2i(1 - subdivision, 1) : Vector2i(1, 0);