ddl: make ddl test more stable (#12503)
ddl: make ddl test more stable (#12503)


ngaut/tidb,pingcap/tidb,qiuyesuifeng/tidb,kyle-wang/tidb,kyle-wang/tidb,EvilMcJerkface/tidb,ming-relax/tidb,Cofyc/tidb,c4pt0r/tidb,coocood/tidb,ngaut/tidb,pingcap/tidb,c4pt0r/tidb,c4pt0r/tidb,XuHuaiyu/tidb,kyle-wang/tidb,qiuyesuifeng/tidb,coocood/tidb,XuHuaiyu/tidb,pingcap/tidb,kyle-wang/tidb,pingcap/tidb,c4pt0r/tidb,ngaut/tidb,ngaut/tidb,ngaut/tidb,c4pt0r/tidb,ngaut/tidb,kyle-wang/tidb,kyle-wang/tidb,pingcap/tidb,Cofyc/tidb,ming-relax/tidb,pingcap/tidb,c4pt0r/tidb,EvilMcJerkface/tidb