Cancel ADD INDEX job with DXF is slow

[CbcWestwolf]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. enable tidb_ddl_enable_fast_reorg and tidb_enable_dist_task
2. set tidb_ddl_reorg_max_write_speed (introduced in ddl: introduce a new system variable to control the store-write-bwlimit when ingesting #57145) to a small speed like 1kb
3. add index in session 1, which would cost some time
4. cancel the add index job in session 2

2. What did you expect to see? (Required)

The job can be canceled in time

3. What did you see instead (Required)

It takes much time for the job state to transfer from 'canceling' to 'rollback done'

4. What is your TiDB version? (Required)

https://github.com/pingcap/tidb/tree/f973f194b21a8e79d42be3a9d4b2db441073f51c with #57145