Update changelogs from fern repo (#1115)

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

Author: fern-support

fern/products/sdks/overview/typescript/changelog/2025-10-03.mdx

@@ -1,3 +1,9 @@
+## 3.3.9
+**`(fix):`** Use `// ... file header ...` file header instead of `/** ... file header ... */`.
+The latter is considered a JSDoc comment and may cause issues with some tools.
+The TypeScript compiler will remove `//` but not `/** */` comments.
+
+
 ## 3.3.7
 **`(fix):`** Dynamically build type for enums based on the const to reduce generated code.