docs: added changelog entry

Signed-off-by: Victor Fernandes <[email protected]>

CHANGELOG.md

@@ -22,7 +22,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 - [#6352](https://github.com/thanos-io/thanos/pull/6352) Store: Expose store gateway query stats in series response hints.
 
 ### Fixed
-
+- [#6427](https://github.com/thanos-io/thanos/pull/6427) Receive: increasing log level for failed uploads to error
 - [#6172](https://github.com/thanos-io/thanos/pull/6172) query-frontend: return JSON formatted errors for invalid PromQL expression in the split by interval middleware.
 - [#6171](https://github.com/thanos-io/thanos/pull/6171) Store: fix error handling on limits.
 - [#6183](https://github.com/thanos-io/thanos/pull/6183) Receiver: fix off by one in multitsdb flush that will result in empty blocks if the head only contains one sample