update changelog

Signed-off-by: Ben Ye <[email protected]>

CHANGELOG.md

@@ -47,6 +47,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 - [#6163](https://github.com/thanos-io/thanos/pull/6163) Receiver: changed max backoff from 30s to 5s for forwarding requests. Can be configured with `--receive-forward-max-backoff`.
 - [#6327](https://github.com/thanos-io/thanos/pull/6327) *: *breaking :warning:* Use histograms instead of summaries for instrumented handlers.
 - [#6322](https://github.com/thanos-io/thanos/pull/6322) Logging: Avoid expensive log.Valuer evaluation for disallowed levels.
+- [#6363](https://github.com/thanos-io/thanos/pull/6363) Store: Check context error when expanding postings.
 
 ### Removed