Pipelined DML cannot ignore its own locks when reading

[ekexium]

Bug Report

Please answer these questions before submitting your issue. Thanks!
ref #50215

1. Minimal reproduce step (Required)

Keep repeating this SQL (to make the dataset large enough and trigger region splits)
insert into t select * from t

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

No errors.

3. What did you see instead (Required)

Resolve lock timeout error, which is reported by coprocessor.

4. What is your TiDB version? (Required)

master(ab90c77)