The US Marshall service, which is the enforcement arm of the court. When the court declared school integration in Brown v. Board of Education, there were some states that refused to comply so the US Marshall service escorted some people to class to make sure it happened. In theory, they could also start performing evictions but that would only be needed if the state refused to comply. I don't see states like Texas listening to the CDC about evictions when even the Supreme Court said to ignore them.