chore: fix JavaScript lint errors (issue #11517)

[bhumikasudarshani-cmd]

Description

Fixes a JavaScript linting error in the @stdlib/utils/async/map-values examples file by replacing string concatenation in an error message with @stdlib/string/format.

Issues

resolves #11517

Changes

1.Added var format = require( '@stdlib/string/format' ); import
2.Replaced 'unable to retrieve stats: '+file with format( 'unable to retrieve stats: %s', file )

• Read, understood, and followed the contributing guidelines

[stdlib-bot]

Hello! Thank you for your contribution to stdlib.

We noticed that the contributing guidelines acknowledgment is missing from your pull request. Here's what you need to do:

1. Please read our contributing guidelines.

2. Update your pull request description to include this checked box:

   - [x] Read, understood, and followed the [contributing guidelines](https://github.com/stdlib-js/stdlib/blob/develop/CONTRIBUTING.md)

This acknowledgment confirms that you've read the guidelines, which include:

• The developer's certificate of origin
• Your agreement to license your contributions under the project's terms

We can't review or accept contributions without this acknowledgment.

Thank you for your understanding and cooperation. We look forward to reviewing your contribution!