test(dm): TestTableSchemaChecking

[okJiang]

Which jobs are flaking?

dm

Which test(s) are flaking?

TestTableSchemaChecking

Jenkins logs or GitHub Actions link

[2022-11-10T02:14:41.559Z] === Failed

[2022-11-10T02:14:41.559Z] === FAIL: dm/checker TestTableSchemaChecking (0.02s)

[2022-11-10T02:14:41.559Z]     check_test.go:400: 

[2022-11-10T02:14:41.559Z]         	Error Trace:	/home/jenkins/agent/workspace/ut-check/tiflow/dm/checker/check_test.go:400

[2022-11-10T02:14:41.559Z]         	Error:      	"Query: could not match actual sql: \"SHOW CREATE TABLE `db_1`.`t_2`\" with expected regexp \"SHOW CREATE TABLE `db_1`.`t_1`\"" does not contain "primary/unique key does not exist"

[2022-11-10T02:14:41.559Z]         	Test:       	TestTableSchemaChecking```

### Anything else we need to know

- Does this test exist for other branches as well?

- Has there been a high frequency of failure lately?