**Description**

It would be nice if the weight_rule default value could be managed by a global config

suggested config:
```
# Weighting method used for the effective total priority weight of the task. 
# Options are: { downstream | upstream | absolute } default is
default_weight_rule = downstream
```
**Use case / motivation**

In some pipeline, you really need to have absolute weight, and then you have to add a line in each task definition which is annoying

airflow/models/baseoperator.py
)
            DagContext.pop_context_managed_dag()
        return cls.__serialized_fields
    def is_smart_sensor_compatible(self):
        """Return if this operator can use smart service. Default False."""
        return False
    @property
    def inherits_from_dummy_operator(self):
        """Used to determine if an Operator is inherited from DummyOperator"""
        
        
        
        return getattr(self, '_is_dummy', False)
    def defer(
        self,
        *,
        trigger: BaseTrigger,
        method_name: str,
        kwargs: Optional[Dict[str, Any]] = None,
        timeout: Optional[timedelta] = None,
    ):
        """
        Marks this Operator as being "deferred" - that is, suspending its
        execution until the provided trigger fires an event.
        This is achieved by raising a special exception (TaskDeferred)
        which is caught in the main _execute_task wrapper.
        """
        raise TaskDeferred(trigger=trigger, method_name=method_name, kwargs=kwargs, timeout=timeout)
Chainable = Union[BaseOperator, "XComArg", EdgeModifier, "TaskGroup"]
def chain(*tasks: Union[Chainable, Sequence[Chainable]]) -> None: