Go でマップのディープ コピーを作成するにはどうすればよいですか?

import (
    "bytes"
    "encoding/gob"
    "fmt"
)

func main() {
    ori := map[string]int{
        "key":  3,
        "clef": 5,
    }

    // Encode the original map
    var mod bytes.Buffer
    enc := gob.NewEncoder(&mod)
    err := enc.Encode(ori)
    if err != nil {
        fmt.Println("Failed to encode map:", err)
        return
    }

    // Decode the encoded map into a new variable (deep copy)
    var cpy map[string]int
    dec := gob.NewDecoder(&mod)
    err = dec.Decode(&cpy)
    if err != nil {
        fmt.Println("Failed to decode map:", err)
        return
    }

    // Modify the copied map to demonstrate they are independent
    cpy["key"] = 2
    fmt.Println("Original map:", ori)
    fmt.Println("Copied map:", cpy)
}