test: migrate constants/float16/ln-two-pi 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 constants/float16/ln-two-pi from relative tolerance assertions to ULP-based assertions, replacing the delta/tol computation with @stdlib/number/float16/base/assert/is-almost-same-value.
• wraps the computed value in @stdlib/number/float64/base/to-float16 before comparison, mirroring the already migrated constants/float16/ln-half and constants/float16/pi-squared packages.
• uses a ULP bound of 0, which is the measured minimum. float64ToFloat16( lnf( 2.0*PI ) ) and the exported constant are bit-for-bit identical (1.837890625), so no slack is required. The suite was run twice at 0 to confirm determinism.

Only test/test.js is changed.

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.

Verification performed locally:

• make test TESTS_FILTER=".*/constants/float16/ln-two-pi/.*" → 4 passing (run twice, identical results).
• make eslint-tests TESTS_FILTER=".*/constants/float16/ln-two-pi/.*" → clean.

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.

This PR was authored by Claude Code, which studied the previously merged migrations in this family, applied the same idiom, and measured the minimum passing ULP bound.

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@stdlib-js/reviewers

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Generated by Claude Code

[stdlib-bot]

Hello! 👋

We've noticed that you've been opening a number of PRs addressing good first issues. Thank you for your interest and enthusiasm!

Now that you've made a few contributions, we suggest no longer working on good first issues. Instead, we encourage you to prioritize cleaning up any PRs which have yet to be merged and then proceed to work on more involved tasks.

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For ideas for future PRs, feel free to search the codebase for TODOs and FIXMEs and be sure to check out other open issues on the issue tracker. Cheers!

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
constants/float16/ln-two-pi	$\\color{green}55/55$ $\\color{green}+100.00\\%$	$\\color{green}1/1$ $\\color{green}+100.00\\%$	$\\color{green}0/0$ $\\color{green}+100.00\\%$	$\\color{green}55/55$ $\\color{green}+100.00\\%$

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