trackbone: avoid using target logger after target run
The target logger writes logs to files in the working dir.
This is useful on the CI because we can show warning/errors to the user in the MR.
However at the end of the target run the working dir is removed unless the keep option is set. Keep is set on the CI.
Usually on local run users don't use the keep option.
What can happen is that while the working dir is removed some logs are written inside causing a race.
Things done:
- removed calls to target.Logger() after target.Run()
- make the target logger private, but ideally Target should be it's own package