### 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)

config->set_value("remap", "importer", "2d_array_texture");
		config->set_value("remap", "type", "CompressedTexture2DArray");
		if (!config->has_section_key("params", "compress/mode")) {
			config->set_value("params", "compress/mode", 2); 
		}
		config->set_value("params", "compress/channel_pack", 1);
		config->set_value("params", "mipmaps/generate", false);
		config->set_value("params", "slices/horizontal", 1);
		config->set_value("params", "slices/vertical", texture_slice_count);
		config->save(texture_path + ".import");
		Error err = texture_image->save_exr(texture_path, false);
		ERR_FAIL_COND_V(err, ret);
		ResourceLoader::import(texture_path);
		Ref<TextureLayered> t = ResourceLoader::load(texture_path); 
		ERR_FAIL_COND_V(t.is_null(), ret);
		ret[i] = t;
	}
	return ret;
}
RID LightmapGIData::get_rid() const {
	return lightmap;
}
void LightmapGIData::clear() {
	users.clear();
}
void LightmapGIData::set_light_texture(const Ref<TextureLayered> &p_light_texture) {
	light_texture = p_light_texture;
	RS::get_singleton()->lightmap_set_textures(lightmap, light_texture.is_valid() ? light_texture->get_rid() : RID(), uses_spherical_harmonics);
}
Ref<TextureLayered> LightmapGIData::get_light_texture() const {