### Godot version

4.0 beta 17

### System information

Windows 11, Forward+, RTX 4090

### Issue description

In the latest beta, baking LightmapGI has taken a big performance hit. The baking itself might not be the problem, it's the (Re)Importing Assets step for the `.exr` that seems to take all the time.




### Steps to reproduce

I've included a repro project to demonstrate it. Click the `LightmapGI` node and then the `Bake Lightmaps` button.

Before Beta 17:
`Done baking lightmaps in 00:00:01.`

With Beta 17 (and the latest Master branch, just in case):
`Done baking lightmaps in 00:00:08.`



### Minimal reproduction project

[lightmap-regression-repro.zip](https://github.com/godotengine/godot/files/10579835/lightmap-regression-repro.zip)

ERR_FAIL_COND(!light_data.is_valid());
	for (int i = 0; i < light_data->get_user_count(); i++) {
		Node *node = get_node(light_data->get_user_path(i));
		int instance_idx = light_data->get_user_sub_instance(i);
		if (instance_idx >= 0) {
			RID instance_id = node->call("get_bake_mesh_instance", instance_idx);
			if (instance_id.is_valid()) {
				RS::get_singleton()->instance_geometry_set_lightmap(instance_id, RID(), Rect2(), 0);
			}
		} else {
			VisualInstance3D *vi = Object::cast_to<VisualInstance3D>(node);
			ERR_CONTINUE(!vi);
			RS::get_singleton()->instance_geometry_set_lightmap(vi->get_instance(), RID(), Rect2(), 0);
		}
	}
}
void LightmapGI::set_light_data(const Ref<LightmapGIData> &p_data) {