[batch] Do not log user errors as exceptions (#14253)

The current lack of this guard means we log exceptions when users submit
jobs with images that don't exist or when users cancel their jobs
(`ContainerDeletedError`). We do this check elsewhere but looks like
this line slipped through.

batch/batch/worker/worker.py

@@ -1877,8 +1877,9 @@ async def on_completion():
  raise
  except ContainerDeletedError as exc:
  log.info(f'Container {container} was deleted while running.', exc)
- except Exception:
- log.exception(f'While running container: {container}')
+ except Exception as e:
+ if not user_error(e):
+ log.exception(f'While running container: {container}')
 
  async def run(self):
  async with self.worker.cpu_sem(self.cpu_in_mcpu):