test/vagrant: Fix NFS setup for test VMs
test/vagrant: Fix NFS setup for test VMs

The well-known 'interrupted system call' errors started popping up in
the test VMs as well. These are caused by newer Go versions being more
strigent with slow system calls through the rsync shared directory.
Using NFS proved to be a good way to avoid these errors in the dev. VMs.

This commit fixes the NFS setup in test VMs to allow for the same
workaround.

Signed-off-by: Paul Chaignon <a027184a55211cd23e3f3094f1fdc728df5e0500@cilium.io>

tgraf/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium