Fix buffer warning

Could you apply the following patch ?

```
ommit 8ef945dad2a3c5223bf92f1431c6899380593c29 (HEAD -> patched)
Author: Bastien Roucariès
Date: Wed Sep 1 18:51:22 2021 +0000

Fix buffer deprecation

Replace by correct API

Forwarded

diff --git a/test/multi-byte.js b/test/multi-byte.js
index 7ad4d57..a753098 100644
--- a/test/multi-byte.js
+++ b/test/multi-byte.js
@@ -3,7 +3,7 @@ var unpack = require('../');
var fs = require('fs');

var src = fs.readFileSync(__dirname + '/files/utf-8.js', 'utf8');
-var buf = new Buffer(src);
+var buf = new Buffer.from(src);

test('multi-byte characters', function (t) {
t.plan(6);
```