Faster Tuist CLI auth on macOS by caching the auth token across calls

The CLI now caches the resolved auth token inside the authentication controller so repeated operations no longer trigger a new keychain read on macOS. Previously every call to fetch the auth token hit securityd, which serializes under concurrency and added noticeable latency on hot paths like the compilation cache daemon. The cache is process-wide and single-flight, and it is invalidated ahead of the token’s expiry so refreshes still run. In practice, concurrent bursts now perform one underlying keychain read instead of one per call, which should noticeably reduce per-operation time on hosted macOS runners.