cask/installer: add workaround for language URLs

[cho-m]

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For now, just add a quick fix to support concurrent installs using JSON API for casks with language specific URLs.

Leaving a FIXME comment as this blocks the main process while downloading Cask source which doesn't align with our usage of download queue.

Ideally should be handled asynchronously.

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Fixes #21094

[Copilot]

Pull request overview

This PR adds a workaround to support concurrent installs for casks with language-specific URLs when using the JSON API. The change modifies the download enqueueing logic to handle casks that require the full caskfile to be loaded.

Key changes:

• Added conditional logic to detect casks with language-specific URLs
• Synchronously loads cask source for language-specific casks before enqueueing downloads
• Maintains async behavior for casks without language specifications

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[MikeMcQuaid]

Thanks @cho-m! Could you open an issue to track this FIXME at some point?

The relevant logic should be porting the load_cask_from_source_api! logic to use the download queue.