Add changelog entry

.changelog/unreleased/breaking-changes/181-event-attribute-bytes.md

@@ -0,0 +1,10 @@
+- Use the v0.34 definition of `abci.Event` which does not enforce 
+  valid UTF-8 data for its `key` and `value` attributes, specifying 
+  them as `bytes` instead of `string`. ([#180](https://github.com/cosmos/ibc-proto-rs/issues/180))
+
+  This is required, because ibc-go emits event attributes which are not valid UTF-8,
+  so we need to use this definition to be able to parse them.
+
+  In Protobuf, `bytes` and `string` are wire-compatible, so doing this strictly increases the amount fo data we can parse.
+
+  See this Hermes PR for background information: https://github.com/informalsystems/hermes/pull/3768