Downgrade gossipsub duplicate logs (#5163)

* Downgrade duplicate publish logs

* Maintain backwards compatiblity, deprecate flag

* The tests had to go, because there's no config to test against

* Update help_bn.md

beacon_node/src/config.rs

@@ -1425,9 +1425,6 @@ pub fn set_network_config(
             Some(config_str.parse()?)
         }
     };
-
-    config.disable_duplicate_warn_logs = cli_args.is_present("disable-duplicate-warn-logs");
-
     Ok(())
 }