infra services that executor depends on should support socket activation

The current list is, these are systemd services that start docker containers before executor:

• salad.service
• minio.service
• fdo-proxy-registry.service
• local-registry.service

The registries may not be possible since the actual implementations of those are from docker(?), and IIRC someone saying that Mars may be going away soon. Minio is also not something we can easily modify, maybe it already supports this?