net/tstun: don't try to set link attributes on android

Android >= 14 forbids the use of netlink sockets.

Fixes #9836

Signed-off-by: David Anderson <dave@tailscale.com>

net/tstun/linkattrs_linux.go

@@ -1,6 +1,8 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
+//go:build !android
+
 package tstun
 
 import (