bench: fix swapped dtypes in size benchmarks

[Planeshifter]

Description

What is the purpose of this pull request?

This pull request:

• Fixes the opts.dtype values in the per-size float32 and float64 benchmark files for @stdlib/ndarray/ones, @stdlib/ndarray/zeros, and @stdlib/ndarray/empty. The values were swapped between the two files in each package, so each file benchmarked the opposite dtype from the one its filename and bench label advertised.

Related Issues

Does this pull request have any related issues?

No.

Questions

Any questions for reviewers of this pull request?

No.

Other

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Scope verified across all ndarray benchmark files: only the three packages above use the opts.dtype pattern. The *-like and ndarray/base/* size benchmarks pass the dtype positionally (e.g., `zeros( 'float32', [len], 'row-major' )`) and were already correct.

Checklist

Please ensure the following tasks are completed before submitting this pull request.

• Read, understood, and followed the contributing guidelines.

AI Assistance

When authoring the changes proposed in this PR, did you use any kind of AI assistance?

• Yes
• No

If you answered "yes" above, how did you use AI assistance?

• Code generation (e.g., when writing an implementation or fixing a bug)
• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

If you answered "yes" to using AI assistance, please provide a short disclosure indicating how you used AI assistance. This helps reviewers determine how much scrutiny to apply when reviewing your contribution. Example disclosures: "This PR was written primarily by Claude Code." or "I consulted ChatGPT to understand the codebase, but the proposed changes were fully authored manually by myself.".

Claude Code identified the swapped dtypes while reviewing @stdlib/ndarray/ones and applied the fix to all affected packages per my instructions.

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@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
ndarray/empty	$\color{green}199/199$ $\color{green}+100.00%$	$\color{green}30/30$ $\color{green}+100.00%$	$\color{green}1/1$ $\color{green}+100.00%$	$\color{green}199/199$ $\color{green}+100.00%$
ndarray/ones	$\color{green}122/122$ $\color{green}+100.00%$	$\color{green}5/5$ $\color{green}+100.00%$	$\color{green}1/1$ $\color{green}+100.00%$	$\color{green}122/122$ $\color{green}+100.00%$
ndarray/zeros	$\color{green}195/195$ $\color{green}+100.00%$	$\color{green}29/29$ $\color{green}+100.00%$	$\color{green}1/1$ $\color{green}+100.00%$	$\color{green}195/195$ $\color{green}+100.00%$

The above coverage report was generated for the changes in this PR.

[kgryte]

LGTM