aws-cdk-lib.aws_applicationautoscaling: DeregisterScalableTarget

### Describe the feature

CDK implementation to Deregister an Application Auto Scaling scalable target after it is finished using it.
A CloudFormation L1 Construct would be great as well for starters.

### Use Case

I am creating sagemaker endpoint and attaching autoscaling policy using scalable targets. During update of that endpoint stack I need to be able to deregister target from that endpoint using CDK.

### Proposed Solution

_No response_

### Other Information

_No response_

### Acknowledgements

- [ ] I may be able to implement this feature request
- [ ] This feature might incur a breaking change

### CDK version used

2.133.0

### Environment details (OS name and version, etc.)

MAC

Start with the aws_applicationautoscaling module and investigate how CDK represents scalable targets, then compare the requested deregistration operation with the relevant AWS CloudFormation resource documentation. Done means CDK can model deregistering an Application Auto Scaling scalable target, including the requested L1 construct, with coverage for the SageMaker endpoint update use case.

Written by the indexing model from the issue text.