Update dependencies

vendor/tailscale.com/clientupdate/clientupdate.go

@@ -27,6 +27,8 @@ import (
 	"strconv"
 	"strings"
 
+	"tailscale.com/hostinfo"
+	"tailscale.com/types/lazy"
 	"tailscale.com/types/logger"
 	"tailscale.com/util/cmpver"
 	"tailscale.com/version"
@@ -169,6 +171,12 @@ func NewUpdater(args Arguments) (*Updater, error) {
 type updateFunction func() error
 
 func (up *Updater) getUpdateFunction() (fn updateFunction, canAutoUpdate bool) {
+	hi := hostinfo.New()
+	// We don't know how to update custom tsnet binaries, it's up to the user.
+	if hi.Package == "tsnet" {
+		return nil, false
+	}
+
 	switch runtime.GOOS {
 	case "windows":
 		return up.updateWindows, true
@@ -242,9 +250,13 @@ func (up *Updater) getUpdateFunction() (fn updateFunction, canAutoUpdate bool) {
 	return nil, false
 }
 
+var canAutoUpdateCache lazy.SyncValue[bool]
+
 // CanAutoUpdate reports whether auto-updating via the clientupdate package
 // is supported for the current os/distro.
-func CanAutoUpdate() bool {
+func CanAutoUpdate() bool { return canAutoUpdateCache.Get(canAutoUpdateUncached) }
+
+func canAutoUpdateUncached() bool {
 	if version.IsMacSysExt() {
 		// Macsys uses Sparkle for auto-updates, which doesn't have an update
 		// function in this package.