### 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(default_args={"execution_timeout": timedelta(minutes=30)}) as dag:
        @dag.task
        def simple(arg):
            pass
        @dag.task
        def mapped(arg):
            pass
        simple(arg=0)
        mapped.expand(arg=[1, 2])
    assert dag.get_task("simple").execution_timeout == timedelta(minutes=30)
    assert dag.get_task("mapped").execution_timeout == timedelta(minutes=30)
@pytest.mark.parametrize(
    "dag_params, task_params, expected_partial_params",
    [
        pytest.param(None, None, ParamsDict(), id="none"),
        pytest.param({"a": -1}, None, ParamsDict({"a": -1}), id="dag"),
        pytest.param(None, {"b": -2}, ParamsDict({"b": -2}), id="task"),
        pytest.param({"a": -1}, {"b": -2}, ParamsDict({"a": -1, "b": -2}), id="merge"),
    ],
)
def test_mapped_expand_against_params(dag_maker, dag_params, task_params, expected_partial_params):
    with dag_maker(params=dag_params) as dag:
        MockOperator.partial(task_id="t", params=task_params).expand(params=[{"c": "x"}, {"d": 1}])
    t = dag.get_task("t")
    assert isinstance(t, MappedOperator)
    assert t.params == expected_partial_params
    assert t.expand_input.value == {"params": [{"c": "x"}, {"d": 1}]}
def test_mapped_render_template_fields_validating_operator(dag_maker, session):
    class MyOperator(MockOperator):