generate-cask-ci-matrix: drop macOS Intel CI

[bevanjkay]

Remove the macos-15-intel runner and the simulated-architecture jobs that ran audit and fetch with --arch=intel on ARM runners, matching the macOS Intel CI removal in Homebrew/brew and Homebrew/homebrew-core. Linux x86_64 is still tested on ubuntu-latest.

Caveats;

• Casks with separate Intel and ARM macOS artifacts no longer have their Intel URL or checksum fetched or audited on macOS.
• Intel-only macOS casks get no macOS jobs at all. A ::warning annotation is emitted when a changed cask has no runner so this is visible on the pull request.

---

• Have you followed our Contributing guidelines?
• Have you checked for other open Pull Requests for the same change?
• Have you explained what your changes do? Performance claims (e.g. "this is faster") must include brew benchmark results.
• Have you explained why you'd like these changes included, not just what they do?
• For bug fixes, have you given step-by-step brew commands to reproduce the bug?
• Have you written new tests (excluding integration tests)? Here's an example.
• Have you successfully run brew lgtm (style, typechecking and tests) locally?

---

• I did not use AI/LLM to create this PR, or I disclosed the tool/model below and reviewed its output; I did not attribute commits to AI and will answer maintainer questions and review comments myself without AI/LLM.

---

I used claude-code with Fable 5.1 to help generate the extended changes.

[Copilot]

🟡 Changes recommended

The empty-runner path can incorrectly audit the whole tap and needs regression coverage.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

Removes macOS Intel and simulated-architecture cask CI while retaining ARM macOS and Linux x86_64 coverage.

Changes:

• Removes Intel macOS runners and cross-architecture jobs.
• Warns when changed casks have no compatible runner.
• Updates runner-selection tests.

File summaries

File	Review
Library/Homebrew/dev-cmd/generate-cask-ci-matrix.rb	Moderate (1 vote): Empty cask jobs can incorrectly trigger whole-tap ARM audits; track selected casks separately. Nit (1 vote): Add coverage verifying the empty matrix and warning for Intel-only casks.
Library/Homebrew/test/dev-cmd/generate-cask-ci-matrix_spec.rb	Updates runner expectations, but lacks coverage for the Intel-only empty-runner path.

Review details

Suppressed comments (1)

Library/Homebrew/dev-cmd/generate-cask-ci-matrix.rb:277

• The warning is the only visibility safeguard for casks that now receive zero test jobs, but no test exercises it: the new specs only call filter_runners/runners, while the integration case uses a supported cask. Please add a generate_matrix example for an Intel-only macOS cask that verifies the empty matrix and this annotation, so a future output or control-flow regression cannot silently leave the cask untested.

          puts "::warning file=#{path}::No CI runner supports this cask, so it will not be tested." if runners.empty?

• Files reviewed: 2/2 changed files
• Comments generated: 1
• Review effort level: Balanced

---

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.

[MikeMcQuaid]

Thanks! Want to 🔥 macOS Intel, but keep Linux Intel.

[MikeMcQuaid]

Thanks!

[krehel]

Thanks for this. Agree the Intel runners are getting worse and ready to 💥 them away.