**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
dag_params.update(params)
            default_args = {}
            if 'default_args' in kwargs:
                default_args = kwargs['default_args']
                if 'params' in default_args:
                    dag_params.update(default_args['params'])
                    del default_args['params']
            dag_args.update(default_args)
            default_args = dag_args
            for arg in sig_cache.parameters:
                if arg not in kwargs and arg in default_args:
                    kwargs[arg] = default_args[arg]
            missing_args = list(non_optional_args - set(kwargs))
            if missing_args:
                msg = f"Argument {missing_args} is required"
                raise AirflowException(msg)
            if dag_params:
                kwargs['params'] = dag_params
            if default_args:
                kwargs['default_args'] = default_args
            if hasattr(self, '_hook_apply_defaults'):
                args, kwargs = self._hook_apply_defaults(*args, **kwargs)
            result = func(self, *args, **kwargs)
            
            self.set_xcomargs_dependencies()
            
            self._BaseOperator__instantiated = True
            return result
        return cast(T, apply_defaults)
    def __new__(cls, name, bases, namespace, **kwargs):