ref(logging): remove LogExt::log_or_ok (#4250)

This further reduces the cognitive overload of having many ways to do
something.  The same is very easily done using composition.  Followup
from 82ace72527.

src/ephemeral.rs

@@ -575,7 +575,8 @@ pub(crate) async fn ephemeral_loop(context: &Context, interrupt_receiver: Receiv
 
         delete_expired_messages(context, time())
             .await
-            .ok_or_log(context);
+            .log_err(context)
+            .ok();
     }
 }