Prepare cask taps before bundle jobs

[MikeMcQuaid]

• Fully qualified casks can need their tap before dependency discovery.
• Loading those deps before scheduling avoids parallel lock races.

Fixes #22899

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[Copilot]

Pull request overview

This pull request adjusts brew bundle’s parallel installer to proactively install taps for fully-qualified cask (and formula) entries before dependency discovery, avoiding parallel lock races and ensuring dependency resolution can load tapped casks correctly.

Changes:

• Ensure taps for fully-qualified Brew/Cask entries are installed before building the dependency graph.
• Add/update RSpec coverage to verify tap installation happens before cask dependency resolution in parallel runs.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
Library/Homebrew/bundle/parallel_installer.rb	Pre-installs required taps for fully-qualified cask/formula entries before dependency discovery and scheduling parallel jobs.
Library/Homebrew/test/bundle/installer_spec.rb	Adds stubs and a new example to assert tap installation precedes cask dependency resolution.

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