Sync anagram tests with problem specifications

[ManasDasri]

Description

Syncs the anagram exercise with the latest canonical test cases from the problem-specifications repository.

Changes

• Added the new canonical test cases for repeated words and case variations.
• Added the new LISTEN anagram case.
• Added the Greek-letter case.
• Added the Unicode character/byte collision case.
• Updated .meta/tests.toml with the new canonical UUIDs and reimplements relationships.
• Marked replaced canonical cases with include = false.

Verification

• git diff --check passes.
• pwsh ./bin/test.ps1 anagram passes with 16/16 tests.

Closes #420

[github-actions]

Hello. Thanks for opening a PR on Exercism 🙂

We ask that all changes to Exercism are discussed on our Community Forum before being opened on GitHub. To enforce this, we automatically close all PRs that are submitted. That doesn't mean your PR is rejected but that we want the initial discussion about it to happen on our forum where a wide range of key contributors across the Exercism ecosystem can weigh in.

You can use this link to copy this into a new topic on the forum. If we decide the PR is appropriate, we'll reopen it and continue with it, so please don't delete your local branch.

If you're interested in learning more about this auto-responder, please read this blog post.

---

Note: If this PR has been pre-approved, please link back to this PR on the forum thread and a maintainer or staff member will reopen it.

[github-actions]

Hello 👋 Thanks for your PR.

This repo does not currently have dedicated maintainers. Our cross-track maintainers team will attempt to review and merge your PR, but it will likely take longer for your PR to be reviewed.

If you enjoy contributing to Exercism and have a track-record of doing so successfully, you might like to become an Exercism maintainer for this track.

Please feel free to ask any questions, or chat to us about anything to do with this PR or the reviewing process on the Exercism forum.

(cc @exercism/cross-track-maintainers)

[github-actions]

This is an unmaintained repository.

Cross-track maintainers - feel free to merge.

[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

If this PR does not affect the result of the test (or, for example, adds an edge case that is not worth rerunning all tests for), please add the following to the merge-commit message which will stops student's tests from re-running. Please copy-paste to avoid typos.

[no important files changed]

For more information, refer to the documentation. If you are unsure whether to add the message or not, please ping @exercism/maintainers-admin in a comment. Thank you!