Posture check: AWS RDS instance not configured with IAM authentication
Query: ```config from cloud.resource where cloud.type = 'aws' AND api.name= 'aws-rds-describe-db-instances' AND json.rule = dbinstanceStatus contains available and dbclusterIdentifier does not exist and (engine contains postgres or engine contains mysql) and engineVersion is not member of (8.0.11, 8.0.13, 8.0.15, 9.6.1, 9.6.2, 9.6.3, 9.6.5, 9.6.6, 9.6.8, 9.6.9, 9.6.10, 10.1, 10.3, 10.4, 10.5) and iamdatabaseAuthenticationEnabled is false```