Add CHANGELOG entry

Signed-off-by: Filip Petkovski <[email protected]>

CHANGELOG.md

@@ -15,7 +15,8 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 - [#5854](https://github.com/thanos-io/thanos/pull/5854) Query Frontend: Handles `lookback_delta` param in query frontend.
 - [#5230](https://github.com/thanos-io/thanos/pull/5230) Rule: Stateless ruler support restoring `for` state from query API servers. The query API servers should be able to access the remote write storage.
 - [#5880](https://github.com/thanos-io/thanos/pull/5880) Query Frontend: Fixes some edge cases of query sharding analysis.
-- [#5893](https://github.com/thanos-io/thanos/pull/5893) Cache: fixed redis client not respecting `SetMultiBatchSize` config value.
+- [#5893](https://github.com/thanos-io/thanos/pull/5893) Cache: Fixed redis client not respecting `SetMultiBatchSize` config value.
+- [#5966](https://github.com/thanos-io/thanos/pull/5966) Query: Fixed mint and maxt when selecting series for the `api/v1/series` HTTP endpoint.
 
 ### Added