Add availability note

ericallam · ericallam · commit 297aec3f340a · 2025-05-03T21:28:16.000+01:00
diff --git a/docs/upgrade-to-v4.mdx b/docs/upgrade-to-v4.mdx
@@ -172,6 +172,8 @@ tasks.onComplete(({ ctx, result }) => {
 
 ### onCancel
 
+<Note>Available in v4.0.0-beta.12 and later.</Note>
+
 You can now define an `onCancel` hook that is called when a run is cancelled. This is useful if you want to clean up any resources that were allocated for the run.
 
 ```ts
