DM internal tables does not have PK so can't work with sql_require_primary_key=ON

[lance6716]

What did you do?

turn on sql_require_primary_key and run DM

What did you expect to see?

no error

What did you see instead?

Unable to create or change a table without a primary key, when the system variable 'sql_require_primary_key' is set. Add a primary key to the table or unset this variable to avoid this message. Note that tables without a primary key can cause performance problems in row-based replication, so please consult your DBA before changing this setting.

Versions of the cluster

all version

current status of DM cluster (execute query-status <task-name> in dmctl)

(paste current status of DM cluster here)

ref pingcap/tidb#57479