Unblock TCP Accept on listener close (V-679)

The owner explicitly requested direct commits on master; --no-verify bypasses the branch-only workflow hook for that instruction.

internal/netaddr/netaddr.go

@@ -188,6 +188,8 @@ func (l *Listener) Accept() (net.Conn, error) {
 	case err := <-l.errc:
 		l.errc <- err
 		return nil, err
+	case <-l.done:
+		return nil, net.ErrClosed
 	}
 }