fix(ecs-patterns): integ test failed with certificate error (#29623)

### Issue # (if applicable)

Part of: #29186 (comment)

### Reason for this change


`aws-ecs-patterns/test/fargate/integ.alb-fargate-service-https-idle-timeout` was failed with certificate error (#29186 (comment)).
It is enough to set `idleTimeout` property to test loadbalancer with idleTimeout.

`aws-ecs-patterns/test/fargate/integ.alb-fargate-service-https` is also failed with certificate error so I will fix at another PR #29649.

### Description of changes


- Rename `aws-ecs-patterns/test/fargate/integ.alb-fargate-service-https-idle-timeout.ts` to `aws-ecs-patterns/test/fargate/integ.alb-fargate-service-idle-timeout.ts`
- Remove unnecessary property
- Run `yarn integ`

### Description of how you validated changes


- Pass integ test

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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