### 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)

Color(0, 0, 0, 0),
			Color(0, 0, 0, 0)
		};
		RD::DrawListID draw_list = RD::get_singleton()->draw_list_begin(p_framebuffer, RD::INITIAL_ACTION_CLEAR, RD::FINAL_ACTION_READ, RD::INITIAL_ACTION_CLEAR, RD::FINAL_ACTION_READ, clear, 1.0, 0, p_region);
		const int uv_offset_count = 9;
		static const Vector2 uv_offsets[uv_offset_count] = {
			Vector2(-1, 1),
			Vector2(1, 1),
			Vector2(1, -1),
			Vector2(-1, -1),
			Vector2(-1, 0),
			Vector2(1, 0),
			Vector2(0, -1),
			Vector2(0, 1),
			Vector2(0, 0),
		};
		for (int i = 0; i < uv_offset_count; i++) {
			Vector2 ofs = uv_offsets[i];
			ofs.x /= p_region.size.width;
			ofs.y /= p_region.size.height;
			render_list_params.uv_offset = ofs;
			_render_list(draw_list, RD::get_singleton()->framebuffer_get_format(p_framebuffer), &render_list_params, 0, render_list_params.element_count); 
		}
		render_list_params.uv_offset = Vector2();
		_render_list(draw_list, RD::get_singleton()->framebuffer_get_format(p_framebuffer), &render_list_params, 0, render_list_params.element_count); 
		RD::get_singleton()->draw_list_end();
	}
	RD::get_singleton()->draw_command_end_label();
}
void RenderForwardMobile::_render_sdfgi(Ref<RenderSceneBuffersRD> p_render_buffers, const Vector3i &p_from, const Vector3i &p_size, const AABB &p_bounds, const PagedArray<RenderGeometryInstance *> &p_instances, const RID &p_albedo_texture, const RID &p_emission_texture, const RID &p_emission_aniso_texture, const RID &p_geom_facing_texture, float p_exposure_normalization) {