refactor: replace fs+util.promisify with fs/promises

lib/ofac/index.js

@@ -1,6 +1,5 @@
-const fs = require('fs')
+const { readdir } = require('fs/promises')
 const path = require('path')
-const util = require('util')
 const loader = require('./loading')
 const matcher = require('./matching')
 const nameUtils = require('./name-utils')
@@ -13,8 +12,6 @@ const OFAC_DATA_DIR = process.env.OFAC_DATA_DIR
 
 let structs = null
 
-const readdir = util.promisify(fs.readdir)
-
 function load () {
   if (!OFAC_DATA_DIR) {
     const message = 'The ofacDataDir option has not been set in the environment'