### Apache Airflow version

main (development)

### What happened

When creating a DAG with Task Groups and a Mapped Operator, if the Task Group is passed as argument to Mapped Operator's `partial` method it is ignored and the operator is not added to the group.

### What you think should happen instead

The Mapped Operator should be added to the Task Group passed as an argument.

### How to reproduce

Create a DAG with a source code like the following one

```python
from airflow import DAG
from airflow.operators.bash import BashOperator
from airflow.operators.empty import EmptyOperator
from airflow.utils import timezone
from airflow.utils.task_group import TaskGroup


with DAG("dag", start_date=timezone.datetime(2016, 1, 1)) as dag:
    start = EmptyOperator(task_id="start")
    finish = EmptyOperator(task_id="finish")

    group = TaskGroup("test-group")
    commands = ["echo a", "echo b", "echo c"]
    mapped = BashOperator.partial(task_id="task_2", task_group=group).expand(bash_command=commands)

    start >> group >> finish

# assert mapped.task_group == group

```

### Operating System

macOS 13.2.1 (22D68)

### Versions of Apache Airflow Providers

_No response_

### Deployment

Other

### Deployment details

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

with dag_maker(session=session):
        task1 = BaseOperator(task_id="op1")
        mapped = MockOperator.partial(task_id="a", arg2="{{ ti.task_id }}").expand_kwargs(task1.output)
    dr = dag_maker.create_dagrun()
    ti: TaskInstance = dr.get_task_instance(task1.task_id, session=session)
    ti.xcom_push(key=XCOM_RETURN_KEY, value=[{"arg1": "{{ ds }}"}, {"arg1": 2}], session=session)
    session.add(
        TaskMap(
            dag_id=dr.dag_id,
            task_id=task1.task_id,
            run_id=dr.run_id,
            map_index=-1,
            length=2,
            keys=None,
        )
    )
    session.flush()
    ti: TaskInstance = dr.get_task_instance(mapped.task_id, session=session)
    ti.refresh_from_task(mapped)
    ti.map_index = map_index
    assert isinstance(ti.task, MappedOperator)
    mapped.render_template_fields(context=ti.get_template_context(session=session))
    assert isinstance(ti.task, MockOperator)
    assert ti.task.arg1 == expected
    assert ti.task.arg2 == "a"
def test_xcomarg_property_of_mapped_operator(dag_maker):