Revert "ssh,tempfork/gliderlabs/ssh: replace github.com/tailscale/golang-x-crypto/ssh with golang.org/x/crypto/ssh"

This reverts commit 46fd4e58a2.

We don't want to include this in 1.80 yet, but can add it back post 1.80.

Updates #8593

Signed-off-by: Percy Wegmann <percy@tailscale.com>

cmd/tailscaled/deps_test.go

@@ -17,6 +17,7 @@ func TestOmitSSH(t *testing.T) {
 		Tags:   "ts_omit_ssh",
 		BadDeps: map[string]string{
 			"tailscale.com/ssh/tailssh":            msg,
+			"golang.org/x/crypto/ssh":              msg,
 			"tailscale.com/sessionrecording":       msg,
 			"github.com/anmitsu/go-shlex":          msg,
 			"github.com/creack/pty":                msg,