### 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.
if self.revision_id not in self.versions:
            self._version_number += 1
            version = StateMachineVersion(
                self, version=self._version_number, description=description
            )
            self.versions[self.revision_id] = version.arn
            return version
        return None
    def delete_version(self, state_machine_version_arn: Arn) -> None:
        source_revision_id = None
        for revision_id, version_arn in self.versions.items():
            if version_arn == state_machine_version_arn:
                source_revision_id = revision_id
                break
        self.versions.pop(source_revision_id, None)
    def itemise(self) -> StateMachineListItem:
        return StateMachineListItem(
            stateMachineArn=self.arn,
            name=self.name,
            type=self.sm_type,
            creationDate=self.create_date,
        )
class StateMachineVersion(StateMachineInstance):
    source_arn: Arn
    version: int
    description: Optional[str]
    def __init__(