test: migrate stats/base/dists/betaprime/quantile to ULP-based assertions

[DivyanshuVortex]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates the tests for stats/base/dists/betaprime/quantile from relative tolerance testing to ULP difference testing, per [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352.
• replaces the legacy y === expected[i] / delta <= tol branch in the fixture loops of the test files with t.strictEqual( isAlmostSameValue( y, expected[ i ], N ), true, 'returns expected value' );.
• adds the @stdlib/assert/is-almost-same-value require and drops any unused abs and EPS requires.

Final ULP constants:

• test.factory.js: 36 ULP (max evaluated ULP: 36 for largeAlpha, 34 for largeBeta, 29 for bothLarge)
• test.quantile.js: 36 ULP (max evaluated ULP: 36 for largeAlpha, 34 for largeBeta, 29 for bothLarge)

These bounds were determined empirically using a script that calculated the maximum ULP difference across all fixture combinations.

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• [RFC]: Migrate math/base/special packages from relative tolerance testing to ULP difference testing (tracking issue) #11352

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.

Test results via make test TESTS_FILTER=".*/stats/base/dists/betaprime/quantile/.*" passed cleanly.

Checklist

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

• Read, understood, and followed the contributing guidelines.

AI Assistance

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• No

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• Test/benchmark generation
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[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/dists/betaprime/quantile	$\\color{green}238/238$ $\\color{green}+100.00\\%$	$\\color{green}23/23$ $\\color{green}+100.00\\%$	$\\color{green}3/3$ $\\color{green}+100.00\\%$	$\\color{green}238/238$ $\\color{green}+100.00\\%$

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

[kgryte]

LGTM