Update dependency pytest-django to v4

This MR contains the following updates:

Package	Type	Update	Change
pytest-django (source, changelog)	dev-dependencies	major	^3.9.0 -> ^4.0.0

---

Release Notes

pytest-dev/pytest-django

v4.5.2

Compare Source

https://pytest-django.readthedocs.io/en/latest/changelog.html#v4-5-2-2021-12-07

v4.5.1

Compare Source

https://pytest-django.readthedocs.io/en/latest/changelog.html#v4-5-1-2021-12-02

v4.5.0

Compare Source

https://pytest-django.readthedocs.io/en/latest/changelog.html#v4-5-0-2021-12-01

v4.4.0

Compare Source

v4.3.0

Compare Source

https://pytest-django.readthedocs.io/en/latest/changelog.html#v4-3-0-2021-05-15

v4.2.0

Compare Source

v4.1.0

Compare Source

https://pytest-django.readthedocs.io/en/latest/changelog.html#v4-1-0-2020-10-22

v4.0.0

Compare Source

https://pytest-django.readthedocs.io/en/latest/changelog.html#v4-0-0-2020-10-16

---

Configuration

📅 Schedule: At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever MR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this MR and you won't be reminded about this update again.

---

• If you want to rebase/retry this MR, click this checkbox.

---

This MR has been generated by Renovate Bot.