**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

tests/models/test_baseoperator.py
#
#
#
import uuid
from datetime import date, datetime
from unittest import mock
import jinja2
import pytest
from airflow.decorators import task as task_decorator
from airflow.exceptions import AirflowException
from airflow.lineage.entities import File
from airflow.models import DAG
from airflow.models.baseoperator import BaseOperator, BaseOperatorMeta, chain, cross_downstream
from airflow.utils.edgemodifier import Label
from airflow.utils.task_group import TaskGroup
from airflow.utils.trigger_rule import TriggerRule
from tests.models import DEFAULT_DATE
from tests.test_utils.mock_operators import DeprecatedOperator, MockNamedTuple, MockOperator
class ClassWithCustomAttributes: