Revert "vagrant: Add NFS backend for file synchronization for OSX."

Reportedly the NFS synced folder type doesn’t work on macOS with the
Docker provider, while the default type does.  And it seems likely
that four years of Ubuntu updates will have resolved the guest crashes
that motivated the prior switch to NFS.

https://chat.zulip.org/#narrow/stream/21-provision-help/topic/experimental.20docker.20setup

This reverts commit 9e8ae68 (zulip#7520).

Signed-off-by: Anders Kaseorg <[email protected]>

Author: andersk

Vagrantfile

@@ -60,13 +60,7 @@ Vagrant.configure(VAGRANTFILE_API_VERSION) do |config|
   ubuntu_mirror = ""
 
   config.vm.synced_folder ".", "/vagrant", disabled: true
-  if (/darwin/ =~ RUBY_PLATFORM) != nil
-    config.vm.synced_folder ".", "/srv/zulip", type: "nfs",
-        linux__nfs_options: ['rw']
-    config.vm.network "private_network", type: "dhcp"
-  else
-    config.vm.synced_folder ".", "/srv/zulip"
-  end
+  config.vm.synced_folder ".", "/srv/zulip"
 
   vagrant_config_file = ENV['HOME'] + "/.zulip-vagrant-config"
   if File.file?(vagrant_config_file)