Update changelogs from fern repo (#995)

Co-authored-by: tjb9dc <[email protected]>

Author: fern-support

fern/products/sdks/overview/python/changelog/2025-09-25.mdx

@@ -1,3 +1,6 @@
+## 4.30.1
+**`(fix):`** Fix sdk `v1_on_v2` export of non-existent `IS_PYDANTIC_V2` variable.
+
 ## 4.30.0
 **`(feat):`** Add support for PR mode for self-hosted/local sdk generation