### Body

Currently when you use multiple-outputs in decorator and it gets None value, it crashes.

As explained in https://github.com/apache/airflow/issues/32553 and workaround for ShortCircuitOperator has been implemented here:  https://github.com/apache/airflow/pull/32569 

But a more complete fix for multiple-outputs handling None is needed. 

### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
num = 2
                @task_decorator
                def add_number(self, num: int) -> int:
                    return self.num + num
    def test_fail_multiple_outputs_key_type(self):
        @task_decorator(multiple_outputs=True)
        def add_number(num: int):
            return {2: num}
        with self.dag:
            ret = add_number(2)
        self.create_dag_run()
        with pytest.raises(AirflowException):
            ret.operator.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE)
    def test_fail_multiple_outputs_no_dict(self):
        @task_decorator(multiple_outputs=True)
        def add_number(num: int):
            return num
        with self.dag:
            ret = add_number(2)
        self.create_dag_run()
        with pytest.raises(AirflowException):
            ret.operator.run(start_date=DEFAULT_DATE, end_date=DEFAULT_DATE)
    def test_multiple_outputs_empty_dict(self):