ddl: prevent returning zero schema version for alter sequence (#36277)
ddl: prevent returning zero schema version for alter sequence (#36277)

close pingcap/tidb#36276
ngaut/tidb,pingcap/tidb,ngaut/tidb,pingcap/tidb,pingcap/tidb,ngaut/tidb,ngaut/tidb,pingcap/tidb,ngaut/tidb,pingcap/tidb,ngaut/tidb,pingcap/tidb