fix(lint): io/ioutil is deprecated

plugin_test.go

@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"io"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"strings"
@@ -410,7 +409,7 @@ func TestWrongFingerprint(t *testing.T) {
 func getHostPublicKeyFile(keypath string) (ssh.PublicKey, error) {
 	var pubkey ssh.PublicKey
 	var err error
-	buf, err := ioutil.ReadFile(keypath)
+	buf, err := os.ReadFile(keypath)
 	if err != nil {
 		return nil, err
 	}