Update changelogs from fern repo (#4440)

Co-authored-by: iamnamananand996 <31537362+iamnamananand996@users.noreply.github.com>

Author: fern-support

fern/products/sdks/overview/rust/changelog/2026-03-20.mdx

@@ -1,3 +1,10 @@
+## 0.20.1
+**`(fix):`** Fix unexpected_cfgs warnings for multipart and sse features by conditionally including
+the execute_multipart_request and execute_sse_request methods in http_client.rs only when
+the corresponding features are needed. Also fix unused Utc import in query_parameter_builder.rs
+and unused SerdeError import in http_client.rs.
+
+
 ## 0.20.0
 **`(feat):`** Reduce dependency footprint by conditionally including dependencies based on IR usage.
 Dependencies like chrono, uuid, num-bigint, ordered-float, and base64 are now only added