Relax swift-transformers version constraint to allow >= 1.2.0

[sebsto]

Summary

WhisperKit's Package.swift uses .upToNextMinor(from: "1.1.6") for the swift-transformers dependency, which caps it at < 1.2.0. This prevents downstream consumers that also depend on FluidAudio from resolving to FluidAudio 0.12.5+, which requires swift-transformers >= 1.2.0.

Problem

With Xcode 26.4 (17E192), the Swift 6 compiler is stricter about concurrency checking. FluidAudio 0.12.4 (the latest version compatible with the current constraint) has sending 'asrManager' risks causing data races errors that fail the build. FluidAudio 0.12.5+ fixes these issues but requires swift-transformers >= 1.2.0.

The build succeeds with Xcode 26.3 (17C529) — this is an Xcode 26.4-specific regression.

Suggested Fix

Widen the swift-transformers dependency in Package.swift:

// Current
.package(url: "https://github.com/huggingface/swift-transformers.git", .upToNextMinor(from: "1.1.6")),

// Proposed
.package(url: "https://github.com/huggingface/swift-transformers.git", from: "1.2.0"),

Environment

• Xcode 26.4 (17E192) — fails
• Xcode 26.3 (17C529) — succeeds
• WhisperKit 0.17.0
• FluidAudio 0.12.4 (capped by swift-transformers constraint)
• macOS 26

[atiorh]

Please see #449. I will leave this issue open until we remove swift-tranformers.