Update changelogs from fern repo (#5443)

Co-authored-by: dsinghvi <10870189+dsinghvi@users.noreply.github.com>

Author: fern-support

fern/products/cli-api-reference/cli-changelog/2026-05-08.mdx

@@ -1,3 +1,10 @@
+## 5.21.1
+**`(chore):`** Bump IR to 67.2.0 to publish the optional `resumable` field added to
+`SseStreamChunk` in PR #15795. Without the IR version bump, no new
+`@fern-fern/ir-sdk` minor was published and the field stayed invisible
+to downstream consumers.
+
+
 ## 5.21.0
 **`(feat):`** Add a new `resumable` sub-property to the `x-fern-streaming` OpenAPI extension
 (and a corresponding `resumable` field on Fern Definition `response-stream`