tests: make read_on_replica stable (#7744)
tests: make read_on_replica stable (#7744)

Signed-off-by: Jay Lee <2b53900d99d9dec83fb079f280f37f8f23b61cc6@gmail.com>
BusyJay/tikv,c4pt0r/tikv,pingcap/tikv,pingcap/tikv,BusyJay/tikv,BusyJay/tikv,BusyJay/tikv