chore: update random value generation and test messages

[hrshya]

Resolves none .

Description

What is the purpose of this pull request?

This pull request:

• Refactors random number generation in JS benchmarks for the math/base/special/gammainc, math/base/special/gammaincinv and math/base/special/gammaln packages.
• Replaces randu() with 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

Any other information relevant to this pull request? This may include screenshots, references, and/or implementation notes.

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
math/base/special/gammainc	$1453/1690$ $+85.98\mathrm{\%}$	$99/134$ $+73.88\mathrm{\%}$	$19/23$ $+82.61\mathrm{\%}$	$1453/1690$ $+85.98\mathrm{\%}$
math/base/special/gammaincinv	$1590/1821$ $+87.31\mathrm{\%}$	$124/153$ $+81.05\mathrm{\%}$	$14/23$ $+60.87\mathrm{\%}$	$1590/1821$ $+87.31\mathrm{\%}$
math/base/special/gammaln	$987/1003$ $+98.40\mathrm{\%}$	$74/82$ $+90.24\mathrm{\%}$	$12/12$ $+100.00\mathrm{\%}$	$987/1003$ $+98.40\mathrm{\%}$

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

[stdlib-bot]

PR Commit Message

chore: update random value generation and test messages

PR-URL: https://github.com/stdlib-js/stdlib/pull/6343

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.