chore: update CHANGELOG.md for v3 (#1108)

* chore: update CHANGELOG.md for v3

Update changelog to include note about fixing SlashPacket compatibility over the Wire

* Update CHANGELOG.md

(cherry picked from commit bcb2b27)

CHANGELOG.md

@@ -8,8 +8,9 @@ Add an entry to the unreleased section whenever merging a PR to main that is not
 
 Date: June 21st, 2023
 
-Interchain Security v3 uses SDK 0.47 and IBC 7. 
+Interchain Security v3 uses SDK 0.47 and IBC 7.
 
+* (fix) [#1093](https://github.com/cosmos/interchain-security/pull/1093) Make SlashPacketData backward compatible when sending data over the wire 
 * (deps) [#1019](https://github.com/cosmos/interchain-security/pull/1019) Bump multiple dependencies. 
   * Bump [cosmos-sdk](https://github.com/cosmos/cosmos-sdk) to [v0.47.3](https://github.com/cosmos/cosmos-sdk/releases/tag/v0.47.3).
   * Bump [ibc-go](https://github.com/cosmos/ibc-go) to [v7.1.0](https://github.com/cosmos/ibc-go/releases/tag/v7.1.0).