On the environment hard limit of coredump is set to zero, coredump test script will fail since the system does not generate coredump. To avoid such issue, set ulimit -c 0 before generating SEGV on the script. Note that scylla-server.service can generate coredump even ulimit -c 0 because we set LimitCORE=infinity on its systemd unit file. Fixes #8238 Closes #8245