Ensure that this works:

```python
@setup
def mytask():
    print("I am a setup task")

with dag_maker() as dag:
    mytask.override(task_id='newtask')

assert len(dag.task_group.children) == 1
setup_task = dag.task_group.children["newtask"]
assert setup_task._is_setup
```
and teardown also works
self.ui_fgcolor = ui_fgcolor
        
        
        self.upstream_group_ids: set[str | None] = set()
        self.downstream_group_ids: set[str | None] = set()
        self.upstream_task_ids = set()
        self.downstream_task_ids = set()
        if SetupTeardownContext.is_setup or SetupTeardownContext.is_teardown:
            
            raise AirflowException("Task groups cannot be marked as setup or teardown.")
    def _check_for_group_id_collisions(self, add_suffix_on_collision: bool):
        if self._group_id is None:
            return
        
        
        if self._group_id in self.used_group_ids:
            if not add_suffix_on_collision:
                raise DuplicateTaskIdFound(f"group_id '{self._group_id}' has already been added to the DAG")
            base = re.split(r"__\d+$", self._group_id)[0]
            suffixes = sorted(
                int(re.split(r"^.+__", used_group_id)[1])
                for used_group_id in self.used_group_ids
                if used_group_id is not None and re.match(rf"^{base}__\d+$", used_group_id)
            )
            if not suffixes:
                self._group_id += "__1"
            else:
                self._group_id = f"{base}__{suffixes[-1] + 1}"
    @classmethod
    def create_root(cls, dag: DAG) -> TaskGroup: