Update changelogs from fern repo (#4565)

Co-authored-by: tstanmay13 <29681256+tstanmay13@users.noreply.github.com>

Author: fern-support

fern/products/sdks/overview/go/changelog/2026-03-26.mdx

@@ -0,0 +1,10 @@
+## 1.31.4
+**`(fix):`** Fix sub-package ErrorCodes maps being empty when errors are declared in a
+different namespace than the endpoints that reference them. The generator now
+groups errors by the service namespace that uses them (via endpoint error
+references) instead of by where they are declared. This ensures that
+sub-packages like `audio/` correctly get populated ErrorCodes with typed
+errors (e.g. BadRequestError, UnauthorizedError) instead of an empty map
+that would cause API errors to be returned as generic `*core.APIError`.
+
+