Update changelogs from fern repo (#561)

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

Author: fern-support

fern/products/cli-api-reference/cli-changelog/2025-08-18.mdx

@@ -1,3 +1,6 @@
+## 0.66.20
+**`(fix):`** Add `kwargs` as a reserved word in python so that generated SDKs continue to compile.
+
 ## 0.66.19
 **`(chore):`** Handle multipart/mixed content types in endpoint responses.