chore: fix JavaScript lint errors (issue #8483)

---
type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes.
report:
  - task: lint_filenames
    status: passed
  - task: lint_editorconfig
    status: passed
  - task: lint_markdown
    status: na
  - task: lint_package_json
    status: na
  - task: lint_repl_help
    status: na
  - task: lint_javascript_src
    status: na
  - task: lint_javascript_cli
    status: na
  - task: lint_javascript_examples
    status: passed
  - task: lint_javascript_tests
    status: na
  - task: lint_javascript_benchmarks
    status: na
  - task: lint_python
    status: na
  - task: lint_r
    status: na
  - task: lint_c_src
    status: na
  - task: lint_c_examples
    status: na
  - task: lint_c_benchmarks
    status: na
  - task: lint_c_tests_fixtures
    status: na
  - task: lint_shell
    status: na
  - task: lint_typescript_declarations
    status: passed
  - task: lint_typescript_tests
    status: na
  - task: lint_license_headers
    status: passed
---

Author: sujal sunil chaudhary

lib/node_modules/@stdlib/fs/read-dir/examples/index.js

@@ -18,20 +18,21 @@
 
 'use strict';
 
+var isError = require( '@stdlib/assert/is-error' );
 var readDir = require( './../lib' );
 
 /* Sync */
 
 var out = readDir.sync( __dirname );
 // returns <Array>
 
-console.log( out instanceof Error );
+console.log( isError( out ) );
 // => false
 
 out = readDir.sync( 'beepboop' );
 // returns <Error>
 
-console.log( out instanceof Error );
+console.log( isError( out ) );
 // => true
 
 /* Async */