logs: migrate away from github.com/apex/log
While we picked apex/log because it had nicer formatting than logrus, it seems that apex/log is no longer maintained and we should probably move to something else (if for no other reason than apex/log still uses github.com/pkg/errors wrapping which we stopped using in #556).
What do you think about moving to https://github.com/rs/zerolog? I'd be happy to assist in the migration.
I saw that but wasn't sure if https://github.com/uber-go/zap is better maintained or not (though according to zap themselves, zerolog is faster).
It would be nice to pick something that is going to be maintained for as long as possible so we don't have to do more migrations in the future (logrus wins out on this metric imho).
Also, let me take a look at how the log formatting looks before starting to work on a port 😅
Maybe we should have an internal logging driver that gets mapped to a different logger. This would also make it nicer to use umoci as a library in other large projects such as in https://github.com/lxc/incus/pull/1880.