### 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.
execution = list(
                filter(lambda e: e.exec_status == execution_status, store.executions.values())
            )
        return execution
    def _idempotent_revision(
        self, context: RequestContext, request: CreateStateMachineInput
    ) -> Optional[StateMachineRevision]:
        
        
        
        
        
        state_machines: list[StateMachineInstance] = list(
            self.get_store(context).state_machines.values()
        )
        revisions = filter(lambda sm: isinstance(sm, StateMachineRevision), state_machines)
        for state_machine in revisions:
            check = all(
                [
                    state_machine.name == request["name"],
                    state_machine.definition == request["definition"],
                    state_machine.sm_type == request.get("type") or StateMachineType.STANDARD,
                    state_machine.logging_config == request.get("loggingConfiguration"),
                    state_machine.tracing_config == request.get("tracingConfiguration"),
                ]
            )
            if check:
                return state_machine
        return None
    def _revision_by_name(