Update dependencies

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

@@ -0,0 +1,34 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package dns
+
+import (
+	"fmt"
+	"os/exec"
+	"syscall"
+
+	"golang.org/x/sys/windows"
+)
+
+func flushCaches() error {
+	cmd := exec.Command("ipconfig", "/flushdns")
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		CreationFlags: windows.DETACHED_PROCESS,
+	}
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("%v (output: %s)", err, out)
+	}
+	return nil
+}
+
+// Flush clears the local resolver cache.
+//
+// Only Windows has a public dns.Flush, needed in router_windows.go. Other
+// platforms like Linux need a different flush implementation depending on
+// the DNS manager. There is a FlushCaches method on the manager which
+// can be used on all platforms.
+func Flush() error {
+	return flushCaches()
+}