Disable log reloading by default (#9966)

* Disable log reloading by default

This disables the log reloading that was enabled by default. The problem
is that the log reload implementation of `tracing` is using a lock to
make the layer replaceable. This lock needs to be locked every time we
need to check if a particular target is enabled (assuming the log level
is high enough). This kills the performance when for example
`sometarget=trace` logging is enabled.

* 🤦

* Remove unused parameter

* Fix test

* Fix

substrate/client/rpc/src/system/tests.rs

@@ -308,7 +308,10 @@ fn test_add_reset_log_filter() {
 
 	// Enter log generation / filter reload
 	if std::env::var("TEST_LOG_FILTER").is_ok() {
-		sc_tracing::logging::LoggerBuilder::new("test_before_add=debug").init().unwrap();
+		let mut builder = sc_tracing::logging::LoggerBuilder::new("test_before_add=debug");
+		builder.with_log_reloading(true);
+		builder.init().unwrap();
+
 		for line in std::io::stdin().lock().lines() {
 			let line = line.expect("Failed to read bytes");
 			if line.contains("add_reload") {