executor: migrate test-infra to testify for distsql_test.go (#31023)
executor: migrate test-infra to testify for distsql_test.go (#31023)

close pingcap/tidb#28574
c4pt0r/tidb,kyle-wang/tidb,ngaut/tidb,kyle-wang/tidb,ngaut/tidb,ngaut/tidb,pingcap/tidb,kyle-wang/tidb,ngaut/tidb,ngaut/tidb,pingcap/tidb,c4pt0r/tidb,ngaut/tidb,pingcap/tidb,pingcap/tidb,kyle-wang/tidb,c4pt0r/tidb,pingcap/tidb,pingcap/tidb,c4pt0r/tidb,c4pt0r/tidb,kyle-wang/tidb,kyle-wang/tidb,c4pt0r/tidb