doc: update node prefix require.cache example

PR-URL: #44724
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Akhil Marsonya <akhil.marsonya27@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/modules.md

@@ -720,7 +720,7 @@ const realFs = require('node:fs');
 const fakeFs = {};
 require.cache.fs = { exports: fakeFs };
 
-assert.strictEqual(require('node:fs'), fakeFs);
+assert.strictEqual(require('fs'), fakeFs);
 assert.strictEqual(require('node:fs'), realFs);
 ```