DBClusterIdentifier: [required] The name of the DB cluster to disassociate the IAM role from.
RoleArn: [required] The Amazon Resource Name (ARN) of the IAM role to disassociate from the DB cluster, for example arn:aws:iam::123456789012:role/NeptuneAccessRole.
FeatureName: The name of the feature for the DB cluster that the IAM role is to be disassociated from. For the list of supported feature names, see describe_db_engine_versions.