chore: address lint errors in plot/unicode/stemleaf

[rajanarahul93]

Summary

This pull request resolves a stdlib/no-new-array ESLint error in the format_data.js utility within the @stdlib/plot/unicode/stemleaf package. The change updates the array initialization and population method to comply with project coding standards.

Root Cause

The code used new Array(number) to pre-allocate an array, which is disallowed by the stdlib/no-new-array lint rule. This rule is in place to prevent common bugs associated with the Array constructor and to promote a consistent coding style using array literals ([]).

Changes

• Replaced out = new Array(data.length) with an empty array literal initialization out = [].
• Changed the method for adding elements to the array from index assignment (out[i] = ...) to out.push(...).

Risk & Rollback

• Risk: Low. This is a non-functional change that only addresses code style. The modified behavior (producing a dense array instead of a sparse one) is more correct for the intended use case.
• Rollback: The commit can be safely reverted using git revert <commit_hash> if any issues are discovered.
• Read, understood, and followed the contributing guidelines

Related

• Closes Fix JavaScript lint errors #8058

[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!

[kgryte]

LGTM

[kgryte]

As the CI failure does not stem from changes introduced in this PR, I'll go ahead and merge.