remove empty list

Signed-off-by: Aolin <[email protected]>

releases/release-8.4.0.md

@@ -450,8 +450,6 @@ The following features are planned for deprecation in future versions:
     - Fix a traffic control issue that might occur after deleting large tables or partitions [#17304](https://github.com/tikv/tikv/issues/17304) @[Connor1996](https://github.com/Connor1996)
     - Fix the issue that TiKV might panic when a stale replica processes Raft snapshots, triggered by a slow split operation and immediate removal of the new replica [#17469](https://github.com/tikv/tikv/issues/17469) @[hbisheng](https://github.com/hbisheng)
 
-+ PD
-
 + TiFlash
 
     - Fix the issue that TiFlash fails to parse the table schema when the table contains Bit-type columns with a default value that contains invalid characters [#9461](https://github.com/pingcap/tiflash/issues/9461) @[Lloyd-Pottiger](https://github.com/Lloyd-Pottiger)