Why doesn't dereferencing a nil pointer in unsafe.Sizeof() cause a panic?

Question

https://go.dev/play/p/X_BH4qGgXHJ

package main

import (
    "fmt"
    "unsafe"
)

func main() {
    var i *int
    fmt.Println(unsafe.Sizeof(*i)) // dereference of null pointer i
}

Why doesn't this code

unsafe.Sizeof(*i)

cause a runtime panic?