Build Cache for Xcode v0.12.3

[system]

What’s Changed

• Bump bitrise-build-cache-cli to v2.6.7 — runtime opt-out for the Bitrise Gradle mirrors init script (ACI-4939). No Xcode-side behaviour change.

Release 0.12.3 · bitrise-steplib/bitrise-step-activate-build-cache-for-xcode