Revert "Also turn on auto-optimize nix store on local dev VMs"

This reverts commit 3113a3e6.

Thinking a second time:  While the staging grid is deployed to
by an automaton anyway and it taking a minute longer won't bother
us, 20 % space savings is probably not worth slowing down
development interactivity.

morph/lib/hardware-vagrant.nix

@@ -26,10 +26,6 @@
     # your boot until you press *.
     boot.initrd.checkJournalingFS = false;
 
-    # Turn on automatic optimization of nix store
-    # https://nixos.wiki/wiki/Storage_optimization
-    nix.autoOptimiseStore = true;
-
     networking.interfaces.enp0s8.ipv4.addresses = [{
       address = config.grid.publicIPv4;
       prefixLength = 24;