JobNotFound kills the worker
```
4|datasets-preview-backend-worker  | DEBUG: 2021-10-27 07:34:30,558 - worker - dataset 'billsum' had error, cache updated
4|datasets-preview-backend-worker  | Traceback (most recent call last):
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/mongoengine/queryset/base.py", line 266, in get
4|datasets-preview-backend-worker  |     result = next(queryset)
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/mongoengine/queryset/base.py", line 1572, in __next__
4|datasets-preview-backend-worker  |     raw_doc = next(self._cursor)
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/pymongo/cursor.py", line 1246, in next
4|datasets-preview-backend-worker  |     raise StopIteration
4|datasets-preview-backend-worker  | StopIteration
4|datasets-preview-backend-worker  | During handling of the above exception, another exception occurred:
4|datasets-preview-backend-worker  | Traceback (most recent call last):
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/io/queue.py", line 107, in finish_job
4|datasets-preview-backend-worker  |     job = Job.objects(id=job_id, started_at__exists=True, finished_at=None).get()
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/mongoengine/queryset/base.py", line 269, in get
4|datasets-preview-backend-worker  |     raise queryset._document.DoesNotExist(msg)
4|datasets-preview-backend-worker  | datasets_preview_backend.io.queue.DoesNotExist: Job matching query does not exist.
4|datasets-preview-backend-worker  | During handling of the above exception, another exception occurred:
4|datasets-preview-backend-worker  | Traceback (most recent call last):
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/worker.py", line 97, in <module>
4|datasets-preview-backend-worker  |     loop()
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/worker.py", line 89, in loop
4|datasets-preview-backend-worker  |     process_next_job()
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/worker.py", line 52, in process_next_job
4|datasets-preview-backend-worker  |     finish_job(job_id)
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/io/queue.py", line 109, in finish_job
4|datasets-preview-backend-worker  |     raise JobNotFound("the job does not exist")
4|datasets-preview-backend-worker  | datasets_preview_backend.io.queue.JobNotFound: the job does not exist
```
JobNotFound kills the worker: ```
4|datasets-preview-backend-worker  | DEBUG: 2021-10-27 07:34:30,558 - worker - dataset 'billsum' had error, cache updated
4|datasets-preview-backend-worker  | Traceback (most recent call last):
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/mongoengine/queryset/base.py", line 266, in get
4|datasets-preview-backend-worker  |     result = next(queryset)
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/mongoengine/queryset/base.py", line 1572, in __next__
4|datasets-preview-backend-worker  |     raw_doc = next(self._cursor)
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/pymongo/cursor.py", line 1246, in next
4|datasets-preview-backend-worker  |     raise StopIteration
4|datasets-preview-backend-worker  | StopIteration
4|datasets-preview-backend-worker  | During handling of the above exception, another exception occurred:
4|datasets-preview-backend-worker  | Traceback (most recent call last):
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/io/queue.py", line 107, in finish_job
4|datasets-preview-backend-worker  |     job = Job.objects(id=job_id, started_at__exists=True, finished_at=None).get()
4|datasets-preview-backend-worker  |   File "/home/hf/.cache/pypoetry/virtualenvs/datasets-preview-backend-CTHb2hp_-py3.9/lib/python3.9/site-packages/mongoengine/queryset/base.py", line 269, in get
4|datasets-preview-backend-worker  |     raise queryset._document.DoesNotExist(msg)
4|datasets-preview-backend-worker  | datasets_preview_backend.io.queue.DoesNotExist: Job matching query does not exist.
4|datasets-preview-backend-worker  | During handling of the above exception, another exception occurred:
4|datasets-preview-backend-worker  | Traceback (most recent call last):
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/worker.py", line 97, in <module>
4|datasets-preview-backend-worker  |     loop()
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/worker.py", line 89, in loop
4|datasets-preview-backend-worker  |     process_next_job()
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/worker.py", line 52, in process_next_job
4|datasets-preview-backend-worker  |     finish_job(job_id)
4|datasets-preview-backend-worker  |   File "/home/hf/datasets-preview-backend/src/datasets_preview_backend/io/queue.py", line 109, in finish_job
4|datasets-preview-backend-worker  |     raise JobNotFound("the job does not exist")
4|datasets-preview-backend-worker  | datasets_preview_backend.io.queue.JobNotFound: the job does not exist
```