### 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)

}
	gi_data->set_light_texture(texture);
	gi_data->set_uses_spherical_harmonics(directional);
	for (int i = 0; i < lightmapper->get_bake_mesh_count(); i++) {
		Dictionary d = lightmapper->get_bake_mesh_userdata(i);
		NodePath np = d["path"];
		int32_t subindex = -1;
		if (d.has("subindex")) {
			subindex = d["subindex"];
		}
		Rect2 uv_scale = lightmapper->get_bake_mesh_uv_scale(i);
		int slice_index = lightmapper->get_bake_mesh_texture_slice(i);
		gi_data->add_user(np, uv_scale, slice_index, subindex);
	}
	{
		
		Vector<Vector3> points;
		Vector<Color> sh;
		points.resize(lightmapper->get_bake_probe_count());
		sh.resize(lightmapper->get_bake_probe_count() * 9);
		for (int i = 0; i < lightmapper->get_bake_probe_count(); i++) {
			points.write[i] = lightmapper->get_bake_probe_point(i);
			Vector<Color> colors = lightmapper->get_bake_probe_sh(i);
			ERR_CONTINUE(colors.size() != 9);
			for (int j = 0; j < 9; j++) {
				sh.write[i * 9 + j] = colors[j];
			}
		}
		
		if (p_bake_step) {