### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

Currently, when passing `$$.Execution.StartTime` as a parameter to a SFN lambda, it is coming in in the format `HH:MM:SS.###`.

### Expected Behavior

`$$.Execution.StartTime` should be an ISO 8601 datetime string.

### How are you starting LocalStack?

With a docker-compose file

### Steps To Reproduce

This is run in a docker compose file.

Step function definition is

```json
{
  "Comment": "Sample SFN",
  "StartAt": "SampleLambda",
  "States": {    
    "SampleLambda": {
      "Type": "Task",
      "Resource": "arn:aws:states:::lambda:invoke",
      "End": true,
      "Parameters": {
        "FunctionName": "Sample-Function",
        "Payload": {
          "data": {
            "startDateTime.$": "$$.Execution.StartTime"
          }
        }
      }
    }
  }
}
```

### Environment

```markdown
- OS: Mac OS Ventura 13.6.1
- LocalStack:
LocalStack version: 3.0.1.dev
LocalStack build date: 2023-11-20
LocalStack build git hash: 3e32b438
```


### Anything else?

Thank you so much for your hard work.
self, context: RequestContext, resource_arn: Arn, tags: TagList
    ) -> TagResourceOutput:
        # 
        state_machines = self.get_store(context).state_machines
        state_machine = state_machines.get(resource_arn)
        if not isinstance(state_machine, StateMachineRevision):
            raise ResourceNotFound(f"Resource not found: '{resource_arn}'")
        state_machine.tag_manager.add_all(tags)
        return TagResourceOutput()
    def untag_resource(
        self, context: RequestContext, resource_arn: Arn, tag_keys: TagKeyList
    ) -> UntagResourceOutput:
        # 
        state_machines = self.get_store(context).state_machines
        state_machine = state_machines.get(resource_arn)
        if not isinstance(state_machine, StateMachineRevision):
            raise ResourceNotFound(f"Resource not found: '{resource_arn}'")
        state_machine.tag_manager.remove_all(tag_keys)
        return UntagResourceOutput()
    def list_tags_for_resource(
        self, context: RequestContext, resource_arn: Arn
    ) -> ListTagsForResourceOutput:
        # 
        state_machines = self.get_store(context).state_machines
        state_machine = state_machines.get(resource_arn)
        if not isinstance(state_machine, StateMachineRevision):
            raise ResourceNotFound(f"Resource not found: '{resource_arn}'")
        tags: TagList = state_machine.tag_manager.to_tag_list()
        return ListTagsForResourceOutput(tags=tags)
    def describe_map_run(