switch all error logs to using *_err macros

src/observability/prelude.rs

@@ -17,7 +17,6 @@ pub(crate) use tracing::Instrument;
 ///
 /// The `parent:` and `target:` arguments from the original macro are not
 /// supported.
-#[allow(unused)]
 macro_rules! event_err {
     ($level:expr, $error:expr, $($rest:tt)+) => {
         ::tracing::event!(