log@2.4.0

c9b21f6f (#2625 by @lucasfernog) Export the LogLevel type.
9629c2f4 (#2600 by @exoego) Adds a new varient TargetKind::Dispatch that allows you to construct arbitrary log targets
686a839c (#2626 by @lucasfernog) Fix iOS app stuck when using the iOS Simulator and the log plugin due to a deadlock when calling os_log too early.

60fc35d3 (#2576 by @3lpsy) Add a tracing feature to the log plugin that emits log messages to the tracing system.