launch_template: enable setting Placement value

### Describe the feature

It would be helpful to have Placement enabled in launch_template so that we could specify dedicated hosts.

https://github.com/aws/aws-cdk/blob/main/packages/%40aws-cdk/aws-ec2/lib/launch-template.ts#L676

### Use Case

I need to specify a dedicated host in order to use Macs

### Proposed Solution

enable ability for us to specify Platform with the L2 construct for launch_template

### Other Information

_No response_

### Acknowledgements

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

### CDK version used

2.44.0

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

ubuntu

Start in packages/@aws-cdk/aws-ec2/lib/launch-template.ts around line 676 and inspect how the launch_template L2 construct exposes its settings. Resolve whether the requested capability is Placement or Platform, then verify that users can specify a dedicated host for Mac instances and that the construct behavior is covered by the repository's existing checks.

Written by the indexing model from the issue text.