- Remove some unused code
- Move some code that is only used once to the calling package
- Use testify assertions for checking the presence of files/directories
* Convert `lib/observability` to `slog` from `logrus`
* Inject slog into `lib/observability`
* Convert `lib/release` to slog
* Migrate to `slog` in `lib/cgroup`
* Fix missed variable
* Convert `lib/auth/join` to slog
* Fix missing logutils import
* Ignore sloglint
* Convert `lib/auditd` to Slog
* Switch `lib/player` to use `slog`
Zac Bergquist