server: improve test coverage of `/debug/zip` api (#13486)
server: improve test coverage of `/debug/zip` api (#13486)


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