### 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)

switch (environment_mode) {
			case ENVIRONMENT_MODE_DISABLED: {
				
			} break;
			case ENVIRONMENT_MODE_SCENE: {
				Ref<World3D> world = get_world_3d();
				if (world.is_valid()) {
					Ref<Environment> env = world->get_environment();
					if (env.is_null()) {
						env = world->get_fallback_environment();
					}
					if (env.is_valid()) {
						environment_image = RS::get_singleton()->environment_bake_panorama(env->get_rid(), true, Size2i(128, 64));
					}
				}
			} break;
			case ENVIRONMENT_MODE_CUSTOM_SKY: {
				if (environment_custom_sky.is_valid()) {
					environment_image = RS::get_singleton()->sky_bake_panorama(environment_custom_sky->get_rid(), environment_custom_energy, true, Size2i(128, 64));
				}
			} break;
			case ENVIRONMENT_MODE_CUSTOM_COLOR: {
				environment_image.instantiate();
				environment_image->initialize_data(128, 64, false, Image::FORMAT_RGBAF);
				Color c = environment_custom_color;
				c.r *= environment_custom_energy;
				c.g *= environment_custom_energy;
				c.b *= environment_custom_energy;
				environment_image->fill(c);
			} break;