Gossipsub logging

[pawanjay176]

Description

In #4988 , we started writing libp2p logs into a file.

After we moved gossipsub behaviour into lighthouse in #5066, there doesn't seem to be any way to get the gossipsub logs as they aren't under the gossipsub dependency and they use tracing log as opposed to slog as rest of lighthouse.

We should have an option to enable these gossipsub logs somehow. A hacky way to I used to enable this was to use stdout as the tracing_subscriber writer instead of std::io::sink.

lighthouse/common/logging/src/lib.rs

Lines 269 to 275 in 10a38a8

	if let Err(e) = tracing_subscriber::fmt()
	.with_env_filter(filter_layer)
	.with_writer(std::io::sink)
	.finish()
	.with(MetricsLayer)
	.with(custom_layer)
	.try_init()

[ackintosh]

This issue has been fixed in #5401. 🎉