fix: change log span formatting event to 'ACTIVE'

  ACTIVE means that we log one event per span, but it logs only when all fields on the span have been defined.

Signed-off-by: KtorZ <matthias.benkort@gmail.com>

crates/amaru/src/bin/amaru/observability.rs

@@ -86,7 +86,7 @@ impl TracingSubscriber<Registry> {
     pub fn init(self) {
         let log_format = || tracing_subscriber::fmt::format().with_ansi(true).compact();
         let log_writer = || io::stderr as fn() -> io::Stderr;
-        let log_events = || FmtSpan::ENTER;
+        let log_events = || FmtSpan::ACTIVE;
         let log_filter = || default_filter(AMARU_LOG_VAR, DEFAULT_AMARU_LOG_FILTER);
 
         match self {