perf: use node: prefix to bypass require.cache call for builtins

See fastify/fastify-static#407

index.js

@@ -1,6 +1,6 @@
 'use strict'
 
-const assert = require('assert')
+const assert = require('node:assert')
 const fp = require('fastify-plugin')
 const CSRF = require('@fastify/csrf')
 const createError = require('@fastify/error')