test: migrate math/base/special/cscd to ULP-based testing

[Planeshifter]

Summary

Migrates math/base/special/cscd test cases from relative-tolerance (EPS-scaled delta/tol) comparisons to ULP-difference assertions using @stdlib/assert/is-almost-same-value, per the guidance in #11352.

• test/test.js and test/test.native.js both updated (native tests are currently skipped in this environment as the native add-on could not be built, but mirror the same ULP value as the JS tests).
• Final ULP constant: ULP = 2 for both the negative-value and positive-value fixture blocks.
• This was determined empirically: ULP = 1 fails (59 assertion failures), ULP = 2 passes all 2009 assertions, confirmed deterministic across two consecutive runs. A direct computation of the exact ULP distance between actual and expected values over both fixture sets confirms a max distance of 2 ULPs.
• No other files were changed.

Resolves a part of #11352.

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Generated by Claude Code

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Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/cscd	$\\color{green}186/186$ $\\color{green}+100.00\\%$	$\\color{green}5/5$ $\\color{green}+100.00\\%$	$\\color{green}2/2$ $\\color{green}+100.00\\%$	$\\color{green}186/186$ $\\color{green}+100.00\\%$

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

[kgryte]

You don't need this variable. Just pass 2 directly to the isAlmostSameValue function. Applies here and for the other updated tests.

[kgryte]

Please address the feedback in the comment above: #13664 (comment)