**Description**
The `airflow.models.baseoperator.chain()` is a very useful and convenient way to add sequential task dependencies in DAGs but the function only supports tasks of a `BaseOperator` type.

**Use case / motivation**
Users who create tasks via the `@task` decorator will not be able to use the `chain()` function to apply sequential dependencies that do not share an `XComArg` implicit dependency.

**Are you willing to submit a PR?**
Absolutely. 🚀 

**Related Issues**
None

airflow/models/baseoperator.py
self,
        task_or_task_list: Union[TaskMixin, Sequence[TaskMixin]],
        edge_modifier: Optional[EdgeModifier] = None,
    ) -> None:
        """
        Set a task or a task list to be directly downstream from the current
        task. Required by TaskMixin.
        """
        self._set_relatives(task_or_task_list, upstream=False, edge_modifier=edge_modifier)
    def set_upstream(
        self,
        task_or_task_list: Union[TaskMixin, Sequence[TaskMixin]],
        edge_modifier: Optional[EdgeModifier] = None,
    ) -> None:
        """
        Set a task or a task list to be directly upstream from the current
        task. Required by TaskMixin.
        """
        self._set_relatives(task_or_task_list, upstream=True, edge_modifier=edge_modifier)
    @property
    def output(self):