feat: 基于KCP的Ping程序，利用目前的传输栈

cmd/kcpping/platform_other.go

@@ -0,0 +1,14 @@
+//go:build !linux
+
+package main
+
+import (
+	"fmt"
+	"io"
+	"runtime"
+	"time"
+)
+
+func runPlatform(cfg config, stdout, stderr io.Writer, now func() time.Time) error {
+	return fmt.Errorf("kcpping is only supported on linux; current GOOS=%s", runtime.GOOS)
+}