Include encryption at rest feature to the docker evnironement for integration-tests

[karol-kokoszka]

As we faced couple of issue when restoring data to multiDC cluster with encryption at rest feature enabled, we would like to include this feature into our integration-tests docker environemnt, so that we can run all the tests against such a setup.

It looks that this feature is for scylla enterprise only, https://enterprise.docs.scylladb.com/stable/operating-scylla/security/encryption-at-rest.html, but the docker compose we use is configurable in terms of what ScyllaDB version to use.

scylla-manager/testing/docker-compose.yaml

Line 3 in d044b17

image: scylladb/agent-${SCYLLA_VERSION}

It can be enabled only when the enterprise version is chosen.