bench: update random value generation

[hrshya]

Resolves none .

Description

What is the purpose of this pull request?

This pull request:

• Refactors random number generation in JS benchmarks for the stats/base/dists/beta/kurtosis, stats/base/dists/beta/logcdf, stats/base/dists/beta/logpdf and stats/base/dists/beta/mean packages.
• Replaces uniform() from @stdlib/random/array/uniform for cleaner and more consistent code.
• Moves the random number generation outside the benchmarking loops.
• Updates the test messages to follow code conventions.

Related Issues

Does this pull request have any related issues?

This pull request:

• resolves no related issues.

Questions

Any questions for reviewers of this pull request?

No.

Other

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No.

Checklist

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

• Read, understood, and followed the contributing guidelines.

---

@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/beta/kurtosis	$\color{green}197/197$ $\color{green}+100.00\%$	$\color{green}8/8$ $\color{green}+100.00\%$	$\color{green}2/2$ $\color{green}+100.00\%$	$\color{green}197/197$ $\color{green}+100.00\%$
stats/base/dists/beta/logcdf	$\color{green}253/253$ $\color{green}+100.00\%$	$\color{green}27/27$ $\color{green}+100.00\%$	$\color{green}3/3$ $\color{green}+100.00\%$	$\color{green}253/253$ $\color{green}+100.00\%$
stats/base/dists/beta/logpdf	$\color{green}386/386$ $\color{green}+100.00\%$	$\color{green}47/47$ $\color{green}+100.00\%$	$\color{green}4/4$ $\color{green}+100.00\%$	$\color{green}386/386$ $\color{green}+100.00\%$
stats/base/dists/beta/mean	$\color{green}185/185$ $\color{green}+100.00\%$	$\color{green}8/8$ $\color{green}+100.00\%$	$\color{green}2/2$ $\color{green}+100.00\%$	$\color{green}185/185$ $\color{green}+100.00\%$

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

[Planeshifter]

Let's get it in.

[stdlib-bot]

PR Commit Message

bench: update random value generation

PR-URL: https://github.com/stdlib-js/stdlib/pull/6811

Co-authored-by: hrshya <harshyadav6078@gmail.com>
Reviewed-by: Philipp Burckhardt <pburckhardt@outlook.com>

Please review the above commit message and make any necessary adjustments.