Update releases/release-7.3.0.md

Author: ran-huang

releases/release-7.3.0.md

@@ -185,6 +185,8 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v7.3/quick-start-with-
 | Configuration file | Configuration parameter | Change type | Description |
 | -------- | -------- | -------- | -------- |
 | TiDB | [`enable-32bits-connection-id`](/tidb-configuration-file.md#enable-32bits-connection-id-new-in-v730) | Newly added | Controls whether to enable the 32-bit connection ID feature. |
+| TiDB | [`in-mem-slow-query-recent-num`](/tidb-configuration-file.md#in-mem-slow-query-recent-num-new-in-v730) | Newly added | Controls the number of recently used slow queries that are cached in memory. |
+| TiDB | [`in-mem-slow-query-topn-num`](/tidb-configuration-file.md#in-mem-slow-query-topn-num-new-in-v730) | Newly added | Controls the number of slowest queries that are cached in memory. |
 | TiKV | [`coprocessor.region-bucket-size`](/tikv-configuration-file.md#region-bucket-size-new-in-v610) | Modified | Changes the default value from `96MiB` to `50MiB`. |
 | TiKV | [`raft-engine.format-version`](/tikv-configuration-file.md#format-version-new-in-v630) | Modified | When using Partitioned Raft KV (`storage.engine="partitioned-raft-kv"`), Ribbon filter is used. Therefore, TiKV changes the default value from `2` to `5`. |
 | TiKV | [`raftdb.max-total-wal-size`](/tikv-configuration-file.md#max-total-wal-size-1) | Modified | When using Partitioned Raft KV (`storage.engine="partitioned-raft-kv"`), TiKV skips writing WAL. Therefore, TiKV changes the default value from `"4GB"` to `1`, meaning that WAL is disabled. |