def validate_manifest_deployments(manifest: Dict[str, Any]) -> None:
    """
    Validate that a manifest's deployments contracts reference existing contract_types.
    """
    if set(("contract_types", "deployments")).issubset(manifest):
        all_contract_types = list(manifest["contract_types"].keys())
        all_deployments = list(manifest["deployments"].values())
        all_deployment_names = extract_contract_types_from_deployments(all_deployments)
        missing_contract_types = set(all_deployment_names).difference(
            all_contract_types
        )
        if missing_contract_types:
            raise ValidationError(
                f"Manifest missing references to contracts: {missing_contract_types}."
            )
Validate that a manifest's deployments contracts reference existing contract_types.