Remove codespell `rare` dictionary from website spellcheck

[UltralyticsAssistant]

Summary

The daily Website links and spellcheck workflow reports valid LVIS class names as spelling errors:

• manger → manager
• trough → through

These are valid nouns in the LVIS class label manger/trough.

Root cause

The Check spelling step in .github/workflows/links.yml runs codespell with:

--builtin clear,rare,informal,en-GB_to_en-US

Codespell's rare dictionary explicitly maps manger to manager and trough to through, so enabling it on rendered website text creates these false positives.

Proposed fix

Remove rare from the workflow's codespell built-ins:

--builtin clear,informal,en-GB_to_en-US

This fixes the source rather than adding individual ignore-list exceptions, while retaining the existing clear typo, informal usage, and US-English checks.

[UltralyticsAssistant]

👋 Hello @UltralyticsAssistant, thank you for submitting this ultralytics/docs 🚀 issue and for clearly documenting the codespell false positives affecting the LVIS class label manger/trough.

This is an automated response, and an Ultralytics engineer will also assist soon. To help us review the proposed workflow change efficiently, please ensure the issue includes:

1. A clear description of the reported behavior and the affected workflow
2. The relevant workflow configuration or a link to the specific file, such as .github/workflows/links.yml
3. The exact codespell output showing the reported false positives
4. Confirmation that the proposed change preserves the intended spelling checks
5. Any relevant workflow run details, logs, or validation results after applying the change

Please also make sure you've searched existing issues to avoid duplicates. If you need to add any additional information, please comment on this issue. 🛠️

Thank you for helping improve the documentation workflow! 🚀