### 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)

if (light_data.is_valid()) {
		if (is_inside_tree()) {
			_clear_lightmaps();
		}
		set_base(RID());
	}
	light_data = p_data;
	if (light_data.is_valid()) {
		set_base(light_data->get_rid());
		if (is_inside_tree()) {
			_assign_lightmaps();
		}
	}
	update_gizmos();
}
Ref<LightmapGIData> LightmapGI::get_light_data() const {