rcu-0.2.6: .hlint.yaml

- arguments: [-XCPP, --cpp-define=HLINT, --cpp-ansi]

- ignore: {name: Reduce duplication}
- ignore: {name: Redundant lambda}
- ignore: {name: Use >=>}
- ignore: {name: Use const}
- ignore: {name: Eta reduce}
- ignore: {name: Avoid lambda}