**Description**
The `airflow.models.baseoperator.chain()` is a very useful and convenient way to add sequential task dependencies in DAGs.  This function has [recently been updated](https://github.com/apache/airflow/issues/16635) to support `BaseOperator` and `XComArgs` but should also be able to support `Labels` as well.

**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 with a `Label`.  This use case can occur when attempting to chain multiple branch labels and the next sequential task.

With the new update (yet to be released), users will receive the following exception when attempting to chain an `XComArg` and `Label`:

```bash
TypeError: Chain not supported between instances of <class 'airflow.utils.edgemodifier.EdgeModifier'> and <class 'airflow.models.xcom_arg.XComArg'>
```


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

**Related Issues**
None

airflow/models/baseoperator.py
"""
        Get list of the direct relatives to the current task, upstream or
        downstream.
        """
        if upstream:
            return self.upstream_list
        else:
            return self.downstream_list
    def __repr__(self):
        return "<Task({self.task_type}): {self.task_id}>".format(self=self)
    @property
    def task_type(self) -> str:
        """@property: type of the task"""
        return self.__class__.__name__
    def add_only_new(self, item_set: Set[str], item: str, dag_id: str) -> None:
        """Adds only new items to item set"""
        if item in item_set:
            self.log.warning('Dependency %s, %s already registered for DAG: %s', self, item, dag_id)
        else:
            item_set.add(item)
    @property
    def roots(self) -> List["BaseOperator"]:
        """Required by TaskMixin"""
        return [self]
    @property
    def leaves(self) -> List["BaseOperator"]:
        """Required by TaskMixin"""
        return [self]
    def _set_relatives(