Public APIs should not use futures, replace with async/await

[Konrad `ktoso` Malawski]

we just noticed that public APIs still are using event loop futures, e.g.:

try otel.start().wait()
InstrumentationSystem.bootstrap(otel.tracer())

Futures should not appear in public APIs, prefer deprecating those immediately and replacing with async functions -- even if internally they just wait on the same event loop future.

[Moritz Lang]

Thanks for bringing this up 🙏 I'm working on a significant refactor of swift-otel that removes NIO from all public APIs, making it an implementation detail. This refactor will result in a 1.0 release, so I'll add this issue to the 1.0 milestone for now.

I don't think we necessarily need an in-between release to wrap the public API if it breaks soon after.

[Konrad `ktoso` Malawski]

Sweet!