test/cmd: use bottle pour for faster test run

[cho-m]

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Bottle pour is faster to test than source-build as it avoids setting up build environment and starting another Ruby process.

Example result for reinstall:

• source: 8.56 seconds ./test/cmd/reinstall_spec.rb:10
• bottle: 4.65 seconds ./test/cmd/reinstall_spec.rb:10

cmd/install_spec only partly benefits as it still needs to run source build tests for options, HEAD, etc.

[Copilot]

Pull request overview

This PR optimizes integration test performance by switching from source builds to bottle pours for faster test execution. The change reduces test execution time significantly (e.g., reinstall tests from ~8.5s to ~4.6s) by avoiding build environment setup and additional Ruby process overhead.

Key Changes

• Added automatic bottle block generation for testball_bottle formula in integration test helper
• Converted upgrade, reinstall, and install tests to use testball_bottle instead of source-built formulas
• Added HOMEBREW_TEMP_CELLAR to test cleanup directories to handle bottle extraction artifacts

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb	Added automatic bottle block generation for testball_bottle formula with SHA256 hash and root URL pointing to test fixtures
Library/Homebrew/test/support/fixtures/bottles/testball_bottle-0.1.all.bottle.tar.gz	Added bottle fixture file for cross-platform testing
Library/Homebrew/test/spec_helper.rb	Added HOMEBREW_TEMP_CELLAR to TEST_DIRECTORIES for proper cleanup
Library/Homebrew/test/cmd/upgrade_spec.rb	Refactored to use testball_bottle instead of testball, updated all references to use consistent formula_name variable
Library/Homebrew/test/cmd/reinstall_spec.rb	Refactored to use testball_bottle, added explicit link call after setup, updated path references
Library/Homebrew/test/cmd/install_spec.rb	Split into two separate tests: one for bottle installation and one for source installation, with appropriate expectations for each

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[MikeMcQuaid]

Makes sense, thanks!