Keep the current internal package API file on brew cleanup -s

[p-linnane]

Every internal Ruby command fetches the current api/internal/packages.<tag>.jws.json before it runs, but #23022 made brew cleanup -s remove every packages.*.jws.json file. A standalone brew cleanup -s therefore deletes the file it just downloaded, and each rerun re-downloads then re-deletes it. Follow-up to #23022, discussed in https://github.com/orgs/Homebrew/discussions/6962.

brew cleanup -s now keeps the packages.*.jws.json file for the current effective tag and only sweeps the others left by older OSes or --os/--arch runs. The kept file is matched by the basename of Homebrew::API::Internal.cached_packages_json_file_path, so an injected cache root still resolves it. This mirrors brew update, which retains the current bottle-tag package file and prunes previous-tag ones. Normal brew cleanup still leaves every file untouched, and formula.jws.json and cask.jws.json are unaffected.

The regression test seeds an injected cache with the current-tag file and a stale one, then asserts scrub keeps the current file, removes the stale one, and leaves formula.jws.json and cask.jws.json in place.

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Claude Code (Opus 4.8) wrote the cleanup change and spec; I reviewed the diff and verified with brew lgtm plus targeted cleanup specs.

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[Copilot]

Pull request overview

Updates Homebrew’s cache scrubbing behavior so brew cleanup -s no longer deletes the current internal package API cache file it just downloaded, avoiding repeated download/delete cycles while still removing older per-tag cache files.

Changes:

• Adjust Cleanup#cache_files to exclude the current effective-tag packages.*.jws.json from scrub deletion while still sweeping other tag files.
• Update the cleanup spec to use an injected cache root and assert only the stale internal package file is removed, while formula.jws.json and cask.jws.json remain.

Reviewed changes

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

File	Description
Library/Homebrew/cleanup.rb	Keeps the current internal packages JWS cache file during scrub by rejecting it from the packages.*.jws.json sweep.
Library/Homebrew/test/cleanup_spec.rb	Refactors the scrub test to seed a temp cache with current+stale packages files and assert only the stale one is removed.

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[MikeMcQuaid]

Thanks!