Update dependencies

vendor/tailscale.com/net/dns/resolvconf.go

@@ -0,0 +1,30 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build linux || freebsd || openbsd
+
+package dns
+
+import (
+	"bytes"
+	"os/exec"
+)
+
+func resolvconfStyle() string {
+	if _, err := exec.LookPath("resolvconf"); err != nil {
+		return ""
+	}
+	output, err := exec.Command("resolvconf", "--version").CombinedOutput()
+	if err != nil {
+		// Debian resolvconf doesn't understand --version, and
+		// exits with a specific error code.
+		if exitErr, ok := err.(*exec.ExitError); ok && exitErr.ExitCode() == 99 {
+			return "debian"
+		}
+	}
+	if bytes.HasPrefix(output, []byte("Debian resolvconf")) {
+		return "debian"
+	}
+	// Treat everything else as openresolv, by far the more popular implementation.
+	return "openresolv"
+}