use node: prefix for requires

mostly because code is being autogenerated by all the AI stuff using
this prefix. it's also used in the stack trace.

src/dns/namecheap.js

@@ -10,7 +10,7 @@ exports = module.exports = {
     wait
 };
 
-const assert = require('assert'),
+const assert = require('node:assert'),
     BoxError = require('../boxerror.js'),
     constants = require('../constants.js'),
     debug = require('debug')('box:dns/namecheap'),
@@ -20,7 +20,7 @@ const assert = require('assert'),
     safe = require('safetydance'),
     superagent = require('@cloudron/superagent'),
     timers = require('timers/promises'),
-    util = require('util'),
+    util = require('node:util'),
     waitForDns = require('./waitfordns.js'),
     xml2js = require('xml2js');