### 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,
        execution_arn: Arn,
        max_results: PageSize = None,
        reverse_order: ReverseOrder = None,
        next_token: PageToken = None,
        include_execution_data: IncludeExecutionDataGetExecutionHistory = None,
    ) -> GetExecutionHistoryOutput:
        # 
        execution: Execution = self._get_execution(context=context, execution_arn=execution_arn)
        history: GetExecutionHistoryOutput = execution.to_history_output()
        return history
    def delete_state_machine(
        self, context: RequestContext, state_machine_arn: Arn
    ) -> DeleteStateMachineOutput:
        # 
        state_machines = self.get_store(context).state_machines
        state_machine = state_machines.get(state_machine_arn)
        if isinstance(state_machine, StateMachineRevision):
            state_machines.pop(state_machine_arn)
            for version_arn in state_machine.versions.values():
                state_machines.pop(version_arn, None)
        return DeleteStateMachineOutput()
    def delete_state_machine_version(