clean up unneeded refs to DWO assets in DS operator sync scripts

Per discussion with Anatolii last week, we can:

• remove the specific DWO tag used in sync*.sh scripts, as we don't use the actual value (it just needs to exist in the CSV, so that the operator doesn't die if the env var isn't set) - https://github.com/redhat-developer/devspaces-images/pull/312

• remove refs to the DWO templates as they're only used by k8s deployments (DEV_WORKSPACE_CONTROLLER_VERSION and DEV_HEADER_REWRITE_TRAEFIK_PLUGIN) in https://github.com/redhat-developer/devspaces/blob/devspaces-3-rhel-8/dependencies/job-config.json#L879-L892 - TODO, need clarification on what to do here.