🐞 Sentry alert caused when deleting users

[jamesstottmoj]

Describe the bug.

When deleting certain users, sentry raises an User.DoesntExist alert when trying to remove a user's S3 bucket access. This could be due to the way tasks are handled and the order of users being deleted. This seems to be a rare occurrence as the vast majority of pruned users did not raise this error.

To Reproduce

1. Go to a user through the all users page
2. Delete user
3. Get an error page

Expected Behaviour

User is deleted on press of button

Additional context

If the users doesn't exist as it's been deleted before trying to remove bucket access, catch the error and complete the task without trying to remove bucket access.