issue: #36686
bug reason:
- The clustering compaction tasks on the datanode were never cleaned up.
- The clustering compaction task contains a mapping from clustering key
to buffer, this caused a large memory leak.
fix:
- clean the tasks on datanode by datacoord when clustering compaction
finished.
- reset the mapping that from clustering key to buffer on datanode when
clustering finished.
Signed-off-by: Cai Zhang <cai.zhang@zilliz.com>
04c306e63f