macos: Use `os_log`
Motivated by the discussion about patch/c1514f85d9fda45820190274d3b979c365c38f06 on Zulip.
I suggest to take a look at how to integrate logs of Radicle node with macOS.
Starting points:
- https://developer.apple.com/documentation/os/generating-log-messages-from-your-code
- https://crates.io/crates/oslog