### 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)

void LightmapGI::_gen_new_positions_from_octree(const GenProbesOctree *p_cell, float p_cell_size, const Vector<Vector3> &probe_positions, LocalVector<Vector3> &new_probe_positions, HashMap<Vector3i, bool> &positions_used, const AABB &p_bounds) {
	for (int i = 0; i < 8; i++) {
		Vector3i pos = p_cell->offset;
		if (i & 1) {
			pos.x += p_cell->size;
		}
		if (i & 2) {
			pos.y += p_cell->size;
		}
		if (i & 4) {
			pos.z += p_cell->size;
		}
		if (p_cell->size == 1 && !positions_used.has(pos)) {
			
			Vector3 real_pos = p_bounds.position + Vector3(pos) * p_cell_size;
			
			int ppcount = probe_positions.size();
			const Vector3 *pp = probe_positions.ptr();
			bool exists = false;
			for (int j = 0; j < ppcount; j++) {
				if (pp[j].is_equal_approx(real_pos)) {
					exists = true;
					break;
				}
			}
			if (!exists) {
				new_probe_positions.push_back(real_pos);
			}
			positions_used[pos] = true;
		}