increase the disko size

keep running out of space when building the disk images so increase them
again and hope that this solves it.

Signed-off-by: Brian McGillion <bmg.avoin@gmail.com>

modules/disko/disko-ab-partitions.nix

@@ -34,7 +34,7 @@
   };
   disko = {
     # 8GB is the recommeneded minimum for ZFS, so we are using this for VMs to avoid `cp` oom errors.
-    memSize = 8192;
+    memSize = 16384;
     extraPostVM = ''
       ${pkgs.zstd}/bin/zstd --compress $out/*raw
       rm $out/*raw