rayon 2.12.0 (new cask)

[nbadal]

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After making any changes to a cask, existing or new, verify:

• The submission is for a stable version or documented exception.
• brew audit --cask --online rayon is error-free.
• brew style --fix rayon reports no offenses.

Additionally, if adding a new cask:

• Named the cask according to the token reference.
• Checked the cask was not already refused (add your cask's name to the end of the search field).
• brew audit --cask --new rayon worked successfully.
• HOMEBREW_NO_INSTALL_FROM_API=1 brew install --cask rayon worked successfully.
• brew uninstall --cask rayon worked successfully.

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• AI was used to generate or assist with generating this PR. Please specify below how you used AI to help you, and what steps you have taken to manually verify the changes, including zap stanza paths.

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