ddl: fix unstable restartWorker test (#21633)
ddl: fix unstable restartWorker test (#21633)

 
c4pt0r/tidb,kyle-wang/tidb,coocood/tidb,kyle-wang/tidb,c4pt0r/tidb,c4pt0r/tidb,pingcap/tidb,kyle-wang/tidb,ngaut/tidb,ngaut/tidb,c4pt0r/tidb,c4pt0r/tidb,kyle-wang/tidb,coocood/tidb,ngaut/tidb,ngaut/tidb,pingcap/tidb,kyle-wang/tidb,c4pt0r/tidb,kyle-wang/tidb,pingcap/tidb,ngaut/tidb,pingcap/tidb,pingcap/tidb,ngaut/tidb,pingcap/tidb