### 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)

return self._dag
    @property  
    def dag(self) -> DAG:  
        """Returns the Operator's DAG if set, otherwise raises an error"""
        if self._dag:
            return self._dag
        else:
            raise AirflowException(f"Operator {self} has not been assigned to a DAG yet")
    @dag.setter
    def dag(self, dag: DAG | None):
        """
        Operators can be assigned to one DAG, one time. Repeat assignments to
        that same DAG are ok.
        """
        from airflow.models.dag import DAG
        if dag is None:
            self._dag = None
            return
        if not isinstance(dag, DAG):
            raise TypeError(f"Expected DAG; received {dag.__class__.__name__}")
        elif self.has_dag() and self.dag is not dag:
            raise AirflowException(f"The DAG assigned to {self} can not be changed.")
        if self.__from_mapped:
            pass  
        elif self.task_id not in dag.task_dict:
            dag.add_task(self)
        elif self.task_id in dag.task_dict and dag.task_dict[self.task_id] is not self:
            dag.add_task(self)
        self._dag = dag
    def has_dag(self):