docs: [LangGraph Server Changelog Bot] Changelog updates for new version(s) (#139)

Automated changelog update created by the LangGraph Server Changelog
Bot.

Feel free to merge anytime.

Author: samecrowder

src/langgraph-platform/langgraph-server-changelog.mdx

@@ -5,6 +5,13 @@ sidebarTitle: Server changelog
 
 [LangGraph Server](/langgraph-platform/langgraph-server) is an API platform for creating and managing agent-based applications. It provides built-in persistence, a task queue, and supports deploying, configuring, and running assistants (agentic workflows) at scale. This changelog documents all notable updates, features, and fixes to LangGraph Server releases.
 
+<a id="2025-08-08"></a>
+## v0.2.126
+- Made access logger headers configurable to enhance logging flexibility.
+- Debounced the Runs.stats function to reduce the frequency of expensive calls and improve performance.
+- Introduced debouncing for sweepers to enhance performance and efficiency (#1147).
+- Acquired a lock for TTL sweeping to prevent database spamming during scale-out operations.
+
 <a id="2025-08-06"></a>
 ## v0.2.125
 - Updated tracing context replicas to use the new format, ensuring compatibility.