### 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,
        max_concurrency: Optional[int],
        tolerated_failure_count: Optional[int],
        tolerated_failure_percentage: Optional[float],
    ) -> None:
        if max_concurrency is not None:
            self.max_concurrency = max_concurrency
        if tolerated_failure_count is not None:
            self.tolerated_failure_count = tolerated_failure_count
        if tolerated_failure_percentage is not None:
            self.tolerated_failure_percentage = tolerated_failure_percentage
        self.update_event.set()
class MapRunRecordPoolManager:
    _pool: dict[LongArn, MapRunRecord]
    def __init__(self):
        self._pool = OrderedDict()
    def add(self, map_run_record: MapRunRecord) -> None:
        self._pool[map_run_record.map_run_arn] = map_run_record
    def get(self, map_run_arn: LongArn) -> Optional[MapRunRecord]:
        return self._pool.get(map_run_arn)
    def get_all(self) -> list[MapRunRecord]:
        return list(self._pool.values())