Update changelog.

Author: vbabanin

source/mongodb-handshake/handshake.md

@@ -553,7 +553,7 @@ support the `hello` command, the `helloOk: true` argument is ignored and the leg
 
 ## Changelog
 
-- 2025-05-20: Add requirement to allow appending to client metadata after `MongoClient` initialization.
+- 2025-06-09: Add requirement to allow appending to client metadata after `MongoClient` initialization.
 - 2024-11-05: Move handshake prose tests from spec file to prose test file.
 - 2024-10-09: Clarify that FaaS and container metadata must both be populated when both are present.
 - 2024-08-16: Migrated from reStructuredText to Markdown.

source/unified-test-format/unified-test-format.md

@@ -3597,6 +3597,8 @@ other specs *and* collating spec changes developed in parallel or during the sam
 
 ## Changelog
 
+- 2025-06-09: Add `appendClientMetadata` operation.
+
 - 2025-06-04: Deprecate the `serverless` runOnRequirement
 
 - 2025-04-25: Drop `_enxcol` collections.