asint64 not run in `run`, but in `comoile`

[chyroc]

package main

import (
	"fmt"

	"github.com/expr-lang/expr"
)

func main() {
	x, err := expr.Compile(`a`, expr.AsInt64())
	if err != nil {
		panic(err)
	}
	fmt.Println(expr.Run(x, map[string]any{
		"a": int64(1),
	}))
}

result:

panic: expected int64, but got interface {}

expected:

1