doc: fix missing variable in deepStrictEqual example

PR-URL: #40396
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Derek Lewis <DerekNonGeneric@inf.is>
Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>

doc/api/assert.md

@@ -690,7 +690,7 @@ are recursively evaluated also by the following rules.
 import assert from 'assert/strict';
 
 // This fails because 1 !== '1'.
-deepStrictEqual({ a: 1 }, { a: '1' });
+assert.deepStrictEqual({ a: 1 }, { a: '1' });
 // AssertionError: Expected inputs to be strictly deep-equal:
 // + actual - expected
 //