Improve redundant packet logs (#4254)

* Output an info log if the broadcasted packet is redundant instead of an error

* Fix redundant packet log

* Add additional information in redundant packet log

* Add changelog entry

.changelog/unreleased/improvements/ibc-relayer/4252-improve-redundant-packet-log.md

@@ -0,0 +1,3 @@
+- Improve log message when broadcasting redundant packet and set it
+  to `INFO` instead of `ERROR`.
+  ([\#4252](https://github.com/informalsystems/hermes/issues/4252))

crates/relayer/src/chain/cosmos/retry.rs

@@ -1,7 +1,7 @@
 use core::time::Duration;
 use std::thread;
 
-use tracing::{debug, error, instrument, warn};
+use tracing::{debug, error, info, instrument, warn};
 
 use ibc_proto::google::protobuf::Any;
 use tendermint::abci::Code;
@@ -149,6 +149,17 @@ async fn do_send_tx_with_account_sequence_retry(
                     Ok(response)
                 }
 
+                Code::Err(code) if response.log.contains("packet messages are redundant") => {
+                    info!(
+                        ?response,
+                        diagnostic = response.log,
+                        ?code,
+                        "broadcast tx was not completed, all packets in tx have been relayed already, no fees were consumed"
+                    );
+
+                    Ok(response)
+                }
+
                 // Gas estimation succeeded, but broadcast_tx_sync failed with unrecoverable error.
                 Code::Err(code) => {
                     // Do not increase the account s.n. since CheckTx step of broadcast_tx_sync has failed.