[Bug]: sparse column is sealed before append batch in mmap mode

[sunby]

Is there an existing issue for this?

• [X] I have searched the existing issues

Environment

- Milvus version: 2.4/master
- Deployment mode(standalone or cluster):
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

sparse column is sealed before append batch in mmap mode

Expected Behavior

No response

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

[yanliang567]

/assign @sunby /unassign