doc(event-cache): update relevant change logs

Signed-off-by: Michael Goldenberg <m@mgoldenberg.net>

crates/matrix-sdk-base/CHANGELOG.md

@@ -19,6 +19,9 @@ All notable changes to this project will be documented in this file.
 - The `LatestEventValue::LocalHasBeenSent` variant gains a new `event_id:
   OwnedEventId` field.
   ([#5977](https://github.com/matrix-org/matrix-rust-sdk/pull/5977))
+- [**breaking**] `RelationalLinkedChunk::apply_updates` returns an error rather
+  than panicking. This is necessary in order to ensure certain behaviors are disallowed.
+  ([#6061](https://github.com/matrix-org/matrix-rust-sdk/pull/6061))
 
 ### Refactor
 

crates/matrix-sdk-indexeddb/CHANGELOG.md

@@ -17,6 +17,9 @@ All notable changes to this project will be documented in this file.
   `room_key_backups_fully_downloaded` field in `Changes`.
   ([#6017](https://github.com/matrix-org/matrix-rust-sdk/pull/6017))
   ([#6044](https://github.com/matrix-org/matrix-rust-sdk/pull/6044))
+- [**breaking**] In `EventCacheStore::handle_linked_chunk_updates`, new chunks may no longer
+  reference chunk identifiers which do not yet exist in the store
+  ([#6061](https://github.com/matrix-org/matrix-rust-sdk/pull/6061))
 
 ### Bug Fixes
 

crates/matrix-sdk-sqlite/CHANGELOG.md

@@ -12,6 +12,9 @@ All notable changes to this project will be documented in this file.
   `room_key_backups_fully_downloaded` field in `Changes`.
   ([#6017](https://github.com/matrix-org/matrix-rust-sdk/pull/6017))
   ([#6044](https://github.com/matrix-org/matrix-rust-sdk/pull/6044))
+- [**breaking**] In `EventCacheStore::handle_linked_chunk_updates`, new chunks may no longer
+  reference chunk identifiers which do not yet exist in the store
+  ([#6061](https://github.com/matrix-org/matrix-rust-sdk/pull/6061))
 
 ### Bug Fixes