Tested with both chart 1.1.0rc1 (i.e. main branch r.n.) and 1.0.0 

in Airflow 2.1.0, scheduler does not exit immediately (this was an issue < 2.1.0), but all tasks fail like this:

```
2021-06-08 15:30:17,167] {scheduler_job.py:1241} ERROR - Executor reports task instance <TaskInstance: sqoop_acquisition.terminate_job_flow 2021-06-08 13:00:00+00:00 [queued]> finished (failed) although the task says its queued. (Info: None) Was the task killed externally?
[2021-06-08 15:30:17,170] {scheduler_job.py:1241} ERROR - Executor reports task instance <TaskInstance: gsheets.state_mapping.to_s3 2021-06-08 14:00:00+00:00 [queued]> finished (failed) although the task says its queued. (Info: None) Was the task killed externally?
[2021-06-08 15:30:17,171] {scheduler_job.py:1241} ERROR - Executor reports task instance <TaskInstance: gsheets.app_event_taxonomy.to_s3 2021-06-08 14:00:00+00:00 [queued]> finished (failed) although the task says its queued. (Info: None) Was the task killed externally?
[2021-06-08 15:30:17,172] {scheduler_job.py:1241} ERROR - Executor reports task instance <TaskInstance: gsheets.strain_flavors.to_s3 2021-06-08 14:00:00+00:00 [queued]> finished (failed) although the task says its queued. (Info: None) Was the task killed externally?
[2021-06-08 15:30:19,053] {scheduler_job.py:1205} INFO - Executor reports execution of reporting_8hr.dev.cannalytics.feature_duration.sql execution_date=2021-06-08 07:00:00+00:00 exited with status failed for try_number 1
[2021-06-08 15:30:19,125] {scheduler_job.py:1241} ERROR - Executor reports task instance <TaskInstance: reporting_8hr.dev.cannalytics.feature_duration.sql 2021-06-08 07:00:00+00:00 [queued]> finished (failed) although the task says its queued. (Info: None) Was the task killed externally?
[2021-06-08 15:30:23,842] {dagrun.py:429} ERROR - Marking run <DagRun gsheets @ 2021-06-08 14:00:00+00:00: scheduled__2021-06-08T14:00:00+00:00, externally triggered: False> failed
```

@kaxil @jedcunningham  do you see this when you run CKE?  Any suggestions?
airflow/jobs/base_job.py
#
#
#
#
from time import sleep
from typing import Optional
from sqlalchemy import Column, Index, Integer, String
from sqlalchemy.exc import OperationalError
from sqlalchemy.orm import backref, foreign, relationship
from sqlalchemy.orm.session import make_transient
from airflow.configuration import conf
from airflow.exceptions import AirflowException
from airflow.executors.executor_loader import ExecutorLoader
from airflow.models import DagRun
from airflow.models.base import ID_LEN, Base
from airflow.models.taskinstance import TaskInstance
from airflow.stats import Stats
from airflow.utils import timezone
from airflow.utils.helpers import convert_camel_to_snake
from airflow.utils.log.logging_mixin import LoggingMixin
from airflow.utils.net import get_hostname
from airflow.utils.platform import getuser
from airflow.utils.session import create_session, provide_session
from airflow.utils.sqlalchemy import UtcDateTime
from airflow.utils.state import State
class BaseJob(Base, LoggingMixin):