test: migrate stats/strided/sstdevtk to ULP-based assertions

[kgryte]

Resolves a part of #11352.

Description

What is the purpose of this pull request?

This pull request:

• migrates the tests for stats/strided/sstdevtk from relative tolerance assertions to ULP-based assertions, replacing the delta/tol computation (delta = abs( v - expected ), tol = 1.0 * EPS * abs( expected )) with isAlmostSameValuef( v, expected, 1 ) via @stdlib/number/float32/base/assert/is-almost-same-value.
• drops the now unused @stdlib/math/base/special/abs and @stdlib/constants/float32/eps requires.
• updates the affected assertion messages to 'returns expected value'.

Files changed (test files only):

• test/test.sstdevtk.js
• test/test.sstdevtk.native.js
• test/test.ndarray.js
• test/test.ndarray.native.js

Final ULP constant: 1 (used in all four test files).

This was tightened from an initial bound of 64. The measured ULP difference for the single affected assertion is exactly 1 for both the JavaScript and C implementations:

expected = float64ToFloat32( sqrt( 53.5/6 ) ) = 2.9860787391662598
sstdevtk (JS)            -> 2.986078977584839, ulpDifferencef = 1
ndarray (JS)             -> 2.986078977584839, ulpDifferencef = 1
sstdevtk (native, C)     -> ulpDifferencef = 1
ndarray (native, C)      -> ulpDifferencef = 1

A bound of 0 ULP fails, confirming 1 is the minimum.

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.

• The test suite was run twice at the final bound of 1 ULP to confirm determinism; the native add-on was built locally (node-gyp rebuild) so that test.*.native.js assertions were actually exercised rather than skipped. All five test files pass (77 assertions, 0 failures) on both runs.
• Linting is clean for the changed files using the project's test ESLint configuration (etc/eslint/.eslintrc.tests.js).
• The editorconfig-checker step could not run in this environment because its binary is downloaded from a GitHub release that outbound network policy blocked. EditorConfig compliance was instead verified manually for the changed files: LF line endings, UTF-8 (ASCII), tab indentation, no trailing whitespace, and a final newline.

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

This PR was written primarily by Claude Code, following the idiom established by previously merged conversions in the same family (e.g. stats/strided/sstdevpn). The ULP bound was measured empirically rather than guessed.

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@stdlib-js/reviewers

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Generated by Claude Code

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/strided/sstdevtk	$\\color{green}350/350$ $\\color{green}+100.00\\%$	$\\color{green}13/13$ $\\color{green}+100.00\\%$	$\\color{green}4/4$ $\\color{green}+100.00\\%$	$\\color{green}350/350$ $\\color{green}+100.00\\%$

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