In Go 1.16 `net.ErrClosed` was exported, removing the need to check the
exact text of "use of closed network connection". The stdlib's net listeners
are all setup for this to be a reality, but on Windows containerd uses the
the go-winio projects named pipe implementation as the listener for services.
Before version 0.6.0 this project returned a different error named
`ErrPipeListenerClosed` for using a closed pipe, where this error was just
an `errors.New` with the same text as `net.ErrClosed`, so checking against
`net.ErrClosed` wasn't possible.
Starting in 0.6.0 go-winio has that error assigned to `net.ErrClosed` directly
so this *should* be alright to finally change.
Signed-off-by: Daniel Canter <dcanter@microsoft.com>