add index disttask not canceled when owner change

[ywqzzy]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. tidb1 start add index.
2. owner change to tidb2.
3. tidb2 receive admin cancel add index command.
4. add index ddl job canceled, but dist task not canceled.
5. then dist task running forever.
   

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

dist task canceled.

3. What did you see instead (Required)

dist task keep retrying.

4. What is your TiDB version? (Required)

[ywqzzy]

Can work around with change the related row in mysql.tidb_global_task table.

[ywqzzy]

/severity major

[ywqzzy]

/remove-severity critical

[ywqzzy]

#49971 may fix this issue, lost log, will reopen it when meet it again.