The OpenVDB delay loading of voxel leaf data using mmap works poorly on network
drives. It has a mechanism to make a temporary local file copy to avoid this,
but we disabled that as it leads to other problems.
Now disable delay loading entirely. It's not clear that this has much benefit
in Blender. For rendering we need to load the entire grid to convert to NanoVDB,
and for geometry nodes there also are no cases where we only need part of grids.