### 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(p_bounces < 0 || p_bounces > 16);
	bounces = p_bounces;
}
int LightmapGI::get_bounces() const {
	return bounces;
}
void LightmapGI::set_bias(float p_bias) {
	ERR_FAIL_COND(p_bias < 0.00001);
	bias = p_bias;
}
float LightmapGI::get_bias() const {
	return bias;
}
void LightmapGI::set_max_texture_size(int p_size) {
	ERR_FAIL_COND_MSG(p_size < 2048, vformat("The LightmapGI maximum texture size supplied (%d) is too small. The minimum allowed value is 2048.", p_size));
	ERR_FAIL_COND_MSG(p_size > 16384, vformat("The LightmapGI maximum texture size supplied (%d) is too large. The maximum allowed value is 16384.", p_size));
	max_texture_size = p_size;
}
int LightmapGI::get_max_texture_size() const {
	return max_texture_size;
}
void LightmapGI::set_generate_probes(GenerateProbes p_generate_probes) {
	gen_probes = p_generate_probes;
}
LightmapGI::GenerateProbes LightmapGI::get_generate_probes() const {
	return gen_probes;
}
void LightmapGI::set_camera_attributes(const Ref<CameraAttributes> &p_camera_attributes) {