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
"""
    Abstract class to be derived for jobs. Jobs are processing items with state
    and duration that aren't task instances. For instance a BackfillJob is
    a collection of task instance runs, but should have its own state, start
    and end time.
    """
    __tablename__ = "job"
    id = Column(Integer, primary_key=True)
    dag_id = Column(
        String(ID_LEN),