set autoflush to false

[malmans2]

Attempting to fix this error:

Traceback (most recent call last):
  File "/opt/conda/lib/python3.10/site-packages/distributed/worker.py", line 3016, in apply_function_simple
    result = function(*args, **kwargs)
  File "/src/cads-worker/cads_worker/worker.py", line 42, in submit_workflow
    func(metadata=metadata, **kwargs)
  File "/src/cacholote/cacholote/cache.py", line 169, in wrapper
    _delete_cache_entry(session, cache_entry)
  File "/src/cacholote/cacholote/cache.py", line 69, in _delete_cache_entry
    session.commit()
  File "/opt/conda/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 1451, in commit
    self._transaction.commit(_to_root=self.future)
  File "/opt/conda/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 827, in commit
    self._assert_active(prepared_ok=True)
  File "/opt/conda/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 601, in _assert_active
    raise sa_exc.PendingRollbackError(
sqlalchemy.exc.PendingRollbackError: This Session's transaction has been rolled back due to a previous exception during flush. To begin a new transaction with this Session, first issue Session.rollback(). Original exception was: (raised as a result of Query-invoked autoflush; consider using a session.no_autoflush block if this flush is occurring prematurely)
(psycopg2.OperationalError) server closed the connection unexpectedly
	This probably means the server terminated abnormally
	before or while processing the request.

[SQL: SELECT cache_entries.key AS cache_entries_key, cache_entries.expiration AS cache_entries_expiration, cache_entries.timestamp AS cache_entries_timestamp, cache_entries.counter AS cache_entries_counter, cache_entries.tag AS cache_entries_tag
FROM cache_entries
WHERE cache_entries.key = %(pk_1)s AND cache_entries.expiration = %(pk_2)s]
[parameters: {'pk_1': '1b57dec30eac3c33ac6d16ee3034801225f8b9406e0ef33509b0d60a', 'pk_2': datetime.datetime(9999, 12, 31, 23, 59, 59, 999999)}]
(Background on this error at: https://sqlalche.me/e/14/e3q8) (Background on this error at: https://sqlalche.me/e/14/7s2a)

[FussyDuck]

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