fix(unittests.test_tester): Replace property with cached_property
fix(unittests.test_tester): Replace property with cached_property

Just so that both base and sub methods use the same wrapper

scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests