### 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)

p_bake_step(0.8, RTR("Generating Probe Volumes"), p_bake_userdata, true);
		}
		Vector<Delaunay3D::OutputSimplex> solved_simplices = Delaunay3D::tetrahedralize(points);
		LocalVector<BSPSimplex> bsp_simplices;
		LocalVector<Plane> bsp_planes;
		LocalVector<int32_t> bsp_simplex_indices;
		PackedInt32Array tetrahedrons;
		for (int i = 0; i < solved_simplices.size(); i++) {
			
			BSPSimplex bsp_simplex;
			for (int j = 0; j < 4; j++) {
				bsp_simplex.vertices[j] = solved_simplices[i].points[j];
			}
			for (int j = 0; j < 4; j++) {
				static const int face_order[4][3] = {
					{ 0, 1, 2 },
					{ 0, 2, 3 },
					{ 0, 1, 3 },
					{ 1, 2, 3 }
				};
				Vector3 a = points[solved_simplices[i].points[face_order[j][0]]];
				Vector3 b = points[solved_simplices[i].points[face_order[j][1]]];
				Vector3 c = points[solved_simplices[i].points[face_order[j][2]]];
				
				Plane p(a, b, c);
				int plane_index = -1;
				for (uint32_t k = 0; k < bsp_planes.size(); k++) {
					if (bsp_planes[k].is_equal_approx_any_side(p)) {
						plane_index = k;
						break;