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

[Planeshifter]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates test/test.native.js of math/base/special/cbrt from relative-tolerance (EPS-based) assertions to exact equality assertions, completing the migration to ULP-based testing for this package. test/test.js was already migrated in test: migrate math/base/special/cbrt to ULP-based testing  #11839, which left the native test file behind.
• computes the minimum required ULP tolerance for every fixture block by direct ULP-difference computation (via @stdlib/number/float64/base/ulp-difference) over all 14 Julia fixture files (7042 cases). The maximum ULP difference is 0 for every block, for both the JavaScript implementation and the native add-on, so plain t.strictEqual( y, expected[ i ], 'returns expected value' ) is used rather than isAlmostSameValue, per maintainer guidance to avoid isAlmostSameValue where values are exactly equal.
• removes the now-unused EPS and abs requires and the delta/tol variables, and collapses the obsolete exact-equality short-circuit branches.

The native results did not diverge from the JavaScript implementation (verified locally on arm64/clang), so no compiler-optimization tolerance notes were needed. All 7049 native assertions pass locally with the add-on built and loaded.

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
• test: migrate math/base/special/cbrt to ULP-based testing  #11839

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.

The minimum ULP values were independently re-verified by a second pass which re-computed the maximum ULP difference per fixture block for both the JavaScript implementation and the compiled native add-on; all blocks are exactly 0 ULP.

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.".

This PR was written primarily by Claude Code, including the test migration and the ULP-minimality computation; an independent automated verification pass (also Claude Code) re-computed the minimum ULP values and reviewed the diff before submission.

---

@stdlib-js/reviewers

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/cbrt	$\\color{red}365/367$ $\\color{green}+99.45\\%$	$\\color{red}17/18$ $\\color{green}+94.44\\%$	$\\color{green}3/3$ $\\color{green}+100.00\\%$	$\\color{red}365/367$ $\\color{green}+99.45\\%$

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