Build Cache for Xcode v0.15.3

[system]

What’s Changed

• Bump bundled Bitrise Build Cache CLI to v3.1.2: adds the auth username command (resolve/set the local-invocation display name) and records ci_provider + username in the local invocation log.

Release 0.15.3 · bitrise-steplib/bitrise-step-activate-build-cache-for-xcode