### 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.
from localstack.services.stepfunctions.asl.component.state.state_type import StateType
from localstack.services.stepfunctions.asl.eval.contextobject.contex_object import State
from localstack.services.stepfunctions.asl.eval.environment import Environment
from localstack.services.stepfunctions.asl.eval.event.event_detail import EventDetails
from localstack.services.stepfunctions.asl.eval.program_state import ProgramRunning
from localstack.services.stepfunctions.asl.utils.encoding import to_json_str
LOG = logging.getLogger(__name__)
class CommonStateField(EvalComponent, ABC):
    name: str
    
    state_type: StateType
    
    
    continue_with: ContinueWith
    def __init__(
        self,
        state_entered_event_type: HistoryEventType,
        state_exited_event_type: Optional[HistoryEventType],
    ):
        
        self.comment: Optional[Comment] = None
        
        
        self.input_path: InputPath = InputPath(InputPath.DEFAULT_PATH)
        
        
        self.output_path: OutputPath = OutputPath(OutputPath.DEFAULT_PATH)
        self.state_entered_event_type: Final[HistoryEventType] = state_entered_event_type
        self.state_exited_event_type: Final[Optional[HistoryEventType]] = state_exited_event_type
    def from_state_props(self, state_props: StateProps) -> None: