feat(events-targets): launchType property for ECS task (#29069)

### Issue # (if applicable)

Closes #28990.

### Reason for this change

There are cases where a task definition is created to be compatible with both EC2 and Fargate, and then we want to run the task in Fargate.

### Description of changes

I created the `launchType` property. The `launchType` is overridden if the property is specified.

### Description of how you validated changes

Both unit and integ tests

### 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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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*