Homebrew 6.0.0 CI and tap trust impact ongoing

Sources: Homebrew blog, GitHub release, HN discussion
Summary: Homebrew 6.0.0, released 2026-06-11, requires explicit trust for third-party taps, enables the internal JSON API by default, and enables Linux build sandboxing via Bubblewrap. CI pipelines that add untrusted taps without explicit --force or equivalent trust grants will start failing. Intel x86_64 macOS moves to Tier 3 in September 2026 and becomes fully unsupported in September 2027.
Why it matters: Any CI pipeline running brew tap against third-party sources needs to add explicit trust handling before the upgrade propagates to runners.
Follow-up: Track September 2026 Intel Tier 3 migration; watch for Gatekeeper-failing cask removal.