Update changelogs from fern repo (#1418)

Co-authored-by: tstanmay13 <[email protected]>

Author: fern-support

fern/products/sdks/overview/java/changelog/2025-10-23.mdx

@@ -1,3 +1,9 @@
+## 3.9.2
+**`(fix):`** Fix nullable field serialization in PATCH requests with wrapped request bodies. Explicit null values
+(Nullable.ofNull()) are now correctly serialized as {"field": null} instead of being omitted like
+Nullable.empty().
+
+
 ## 3.9.1
 **`(fix):`** Fix raw client methods to return union types instead of first variant when using response
 properties (x-fern-sdk-return-value) with discriminated or undiscriminated unions.