cmd/tailscale/cli: unhide `--posture-checking` flag to `set`

Updates #5902

Signed-off-by: Anton Tolchanov <anton@tailscale.com>

cmd/tailscale/cli/set.go

@@ -83,7 +83,7 @@ func newSetFlagSet(goos string, setArgs *setArgsT) *flag.FlagSet {
 	setf.BoolVar(&setArgs.advertiseConnector, "advertise-connector", false, "offer to be an app connector for domain specific internet traffic for the tailnet")
 	setf.BoolVar(&setArgs.updateCheck, "update-check", true, "notify about available Tailscale updates")
 	setf.BoolVar(&setArgs.updateApply, "auto-update", false, "automatically update to the latest available version")
-	setf.BoolVar(&setArgs.postureChecking, "posture-checking", false, hidden+"allow management plane to gather device posture information")
+	setf.BoolVar(&setArgs.postureChecking, "posture-checking", false, "allow management plane to gather device posture information")
 	setf.BoolVar(&setArgs.runWebClient, "webclient", false, "expose the web interface for managing this node over Tailscale at port 5252")
 	setf.StringVar(&setArgs.relayServerPort, "relay-server-port", "", hidden+"UDP port number (0 will pick a random unused port) for the relay server to bind to, on all interfaces, or empty string to disable relay server functionality")