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/test/syslog-test.js

@@ -7,9 +7,9 @@
 'use strict';
 
 const expect = require('expect.js'),
-    fs = require('fs'),
-    net = require('net'),
-    path = require('path'),
+    fs = require('node:fs'),
+    net = require('node:net'),
+    path = require('node:path'),
     paths = require('../paths.js'),
     safe = require('safetydance'),
     syslogServer = require('../../syslog.js'),