simulator: Write dependency logs to separate files (#7433)

This PR relates to:
- https://github.com/sigp/lighthouse/pull/7199
- -> workspace_filter has been enabled (dependency logging has been disabled)
- https://github.com/sigp/lighthouse/pull/7394
- -> file logging has been optionally enabled

Building on these, this PR enables dependency logging for the simulators. The logs are written to separate files.

The libp2p/discv5 logs:
- are saved to the directory  specified with `--log-dir`
- respects the `RUST_LOG` environment variable for log level configuration

Cargo.lock

@@ -8384,6 +8384,7 @@ dependencies = [
  "sensitive_url",
  "serde_json",
  "tokio",
+ "tracing",
  "tracing-subscriber",
  "types",
 ]