Release v0.6.1

v0.6.1 (2022-03-05)

Fixes

• Also handle db.InterfaceError when retrying database-related operations (thanks @zmmfsj-z).
• Add unique_job_executions constraint to ensure that only one DjangoJobExecution can be created for
  each DjangoJob for a specific run time (Mitigates #156).
• Update CI configuration to test on Django 3.2 and 4.0, and Python 3.10 (Resolves #163).
• Drop official support for Django<3.2 and Python<3.8. This is slightly ahead of the official dates published in
  https://www.djangoproject.com/download/ and https://devguide.python.org/#status-of-python-branches, but makes the test
  workflows simpler and easier to maintain. If you are using older releases they might still work...