Fix spurious test-bot missing :all bottle warning

[p-linnane]

The test-bot "missing :all bottle" warning misfired on every per-platform job of Homebrew/homebrew-core#291991 (webfont 12.5.0): each job saw only its own platform's bottle JSON and warned, even though the final brew bottle --merge then created a new :all bottle because the generated checksums and cellars matched.

annotate_missing_all_bottle now mirrors the gates brew bottle --merge actually uses to decide all_bottle, so it only warns when the final merge genuinely cannot recreate one. It stays quiet when the formula already has an all: stanza, when a local all bottle JSON is present, when only one platform JSON exists (a single runner cannot know what the multi-platform merge will produce), and when every local tag hash shares one cellar and checksum. A new local_bottle_tag_hashes helper collects the local JSONs and normalizes the top-level "cellar" into each per-tag hash to match the shape the merge builds.

The annotation is informational and never blocks merge, and the authoritative "should have had an :all bottle" check still runs in the final brew bottle --merge, so this only trims false positives from the per-runner heads-up.

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• AI was used to generate or assist with generating this PR.

Claude Code (Opus 4.8) developed the fix and tests; I reviewed the diff and verified with brew lgtm plus targeted test_bot/formulae specs.

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[Copilot]

Pull request overview

This PR adjusts test-bot’s annotate_missing_all_bottle warning logic to avoid false positives on per-platform CI jobs by aligning the predictor’s gating conditions with the ones used when brew bottle --merge determines whether an :all bottle can be (re)created.

Changes:

• Update annotate_missing_all_bottle to short-circuit when an all tag is already present locally, when there’s only a single local bottle JSON, or when local tag hashes share the same (cellar, sha256) pair (indicating an :all bottle can be formed).
• Add local_bottle_tag_hashes to aggregate local bottle JSONs and normalize top-level "cellar" into per-tag hashes.
• Expand unit tests to cover the new gating behavior (local all present, single-platform JSON, differing cellars, and convergent platform bottles).

Reviewed changes

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

File	Description
Library/Homebrew/test_bot/formulae.rb	Refines the “missing :all bottle” annotation predictor to use merge-equivalent gates and adds a helper to aggregate/normalize local bottle JSON tag data.
Library/Homebrew/test/test_bot/formulae_spec.rb	Refactors test setup and adds coverage for the new annotation gating scenarios to prevent per-runner false positives.

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[MikeMcQuaid]

Thanks for fix!