Hello,,

The [new Celery 5.0](https://docs.celeryproject.org/en/stable/whatsnew-5.0.html) has been released and we may consider migrating to this version. I don't know if it has to happen now, if we should wait for version 5.1 or do it now. I am creating this ticket to track this version.

To process this issue, we should consider the consequences of this update, update the CLI calls, update API calls, and test these versions thoroughly.

@auvipy Can you tell a little more about this release? Is this release stable enough to update our project to these versions?  What consequences could this update have?

tests/executors/test_celery_executor.py
import unittest
from datetime import datetime, timedelta
from unittest import mock
import celery.contrib.testing.tasks  
import pytest
from celery import Celery
from celery.backends.base import BaseBackend, BaseKeyValueStoreBackend
from celery.backends.database import DatabaseBackend
from celery.contrib.testing.worker import start_worker
from celery.result import AsyncResult
from kombu.asynchronous import set_event_loop
from parameterized import parameterized
from airflow.configuration import conf
from airflow.exceptions import AirflowException, AirflowTaskTimeout
from airflow.executors import celery_executor
from airflow.executors.celery_executor import BulkStateFetcher
from airflow.models.baseoperator import BaseOperator
from airflow.models.dag import DAG
from airflow.models.taskinstance import SimpleTaskInstance, TaskInstance, TaskInstanceKey
from airflow.operators.bash import BashOperator
from airflow.utils import timezone
from airflow.utils.state import State
from tests.test_utils import db
def _prepare_test_bodies():
    if 'CELERY_BROKER_URLS' in os.environ:
        return [(url,) for url in os.environ['CELERY_BROKER_URLS'].split(',')]
    return [(conf.get('celery', 'BROKER_URL'))]
class FakeCeleryResult:
    @property
    def state(self):