Update changelogs from fern repo (#5245)

Co-authored-by: dsinghvi <10870189+dsinghvi@users.noreply.github.com>

Author: fern-support

fern/products/sdks/generators/go/changelog/2026-04-29.mdx

@@ -1,3 +1,16 @@
+## 1.39.1
+**`(fix):`** Fix OAuth token endpoint to use application/x-www-form-urlencoded content type.
+Per RFC 6749 §4.4.2, the OAuth 2.0 client credentials token request must be
+form-encoded. The generated raw_client.go now emits the correct Content-Type
+header for the token endpoint instead of application/json.
+
+
+**`(fix):`** Fix wire test generation for endpoints with service-level base-path parameters.
+The wiremock mapping now includes service and root path parameters alongside
+endpoint path parameters, so test verification URLs use actual example values
+instead of URL-encoded placeholder syntax.
+
+
 ## 1.39.0
 **`(feat):`** Add `retryStatusCodes` config with `"legacy"` and `"recommended"` modes. Legacy (default)
 preserves current behavior (408, 429, >= 500). Recommended retries only transient