Build Cache for Xcode v0.28.3

Changelog
1

What’s Changed

  • Bump CLI to v3.12.4 (catches up v3.12.3, which the previous 0.x release skipped). Includes: FindMissingBlobs batch cap at 1000 digests + read-path pre-check on cache restore — reduces DeadlineExceeded errors and avoids downloading N-1 blobs on partial-cache misses.
  • Reminder: the 0.x line is deprecated — pin @1 for continued updates.