**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
"""
        Lock task for execution to disable custom action in __setattr__ and
        returns a copy of the task
        """
        other = copy.copy(self)
        other._lock_for_execution = True
        return other
    def set_xcomargs_dependencies(self) -> None:
        """
        Resolves upstream dependencies of a task. In this way passing an ``XComArg``
        as value for a template field will result in creating upstream relation between
        two tasks.
        **Example**: ::
            with DAG(...):
                generate_content = GenerateContentOperator(task_id="generate_content")
                send_email = EmailOperator(..., html_content=generate_content.output)
            # This is equivalent to
            with DAG(...):
                generate_content = GenerateContentOperator(task_id="generate_content")
                send_email = EmailOperator(
                    ..., html_content="{{ task_instance.xcom_pull('generate_content') }}"
                )
                generate_content >> send_email
        """
        from airflow.models.xcom_arg import XComArg
        def apply_set_upstream(arg: Any):