Update changelogs from fern repo (#5580)

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

Author: fern-support

fern/products/sdks/generators/csharp/changelog/2026-05-20.mdx

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+## 2.66.5
+**`(fix):`** Mock-server tests now serialize nullable date-time query and header parameters with millisecond precision so they match what the runtime sends. Previously, when a date-time field was wrapped in a nullable container (e.g. with `respect-nullable-schemas: true` and `coerce-optional-schemas-to-nullable: false`), the generated `WithParam("since", "2024-01-15T09:30:00Z")` omitted milliseconds while the SDK actually sent `2024-01-15T09:30:00.000Z`, causing WireMock to return 404.
+
+

fern/products/sdks/generators/go/changelog/2026-05-20.mdx

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+## 1.42.1
+**`(fix):`** Fix dynamic snippet generation for enum path parameters. Path parameters inlined as
+struct fields on a wrapped request now use the enum value directly (e.g.
+`Action: prelude.ActionAllow`) instead of `.Ptr()`, which produced a typecheck error
+when the struct field is a non-pointer required enum. Path parameters passed as
+positional function arguments continue to use `.Ptr()` when the SDK signature takes
+a pointer.
+
+