Performance degradation with Node 21/22/23+

There is a major drop in performance when upgrading from Node 20 to Node 21/22+

Running the code below on Node 20:

SSH Connection: 2.579s
SFTP Session: 923.811ms
Directory Listing: 1.232s

Running the exact same code on Node 21/22/23:

SSH Connection: 3.304s
SFTP Session: 1.986s
Directory Listing: 2.625s

Creating an SFTP session and doing a readdir are over 2x slower. This adds up when doing several readdir over large directories.

const { Client } = require('ssh2');

const conn = new Client();
console.time('SSH Connection');

conn
  .on('ready', () => {
    console.timeEnd('SSH Connection');
    console.time('SFTP Session');
    conn.sftp(function (err, sftp) {
      if (err) throw err;
      console.timeEnd('SFTP Session');
      console.time('Directory Listing');
      sftp.readdir('/', function (err, list) {
        if (err) throw err;
        console.timeEnd('Directory Listing');
        //console.log(list);
        conn.end();
      });
    });
  })
  .connect({
    host: 'remotehost',
    port: 22,
    username: 'demo',
    password: 'password',
  });

Start by running the supplied SSH/SFTP benchmark with the same remote host across Node 20, 21, 22, and 23+. Compare the connection, SFTP session, and root-directory readdir timings to confirm the regression. Done means the cause is identified and the performance degradation is fixed or clearly documented with supporting measurements.