Bump pytest-django from 4.5.2 to 4.8.0

Bumps [pytest-django](https://github.com/pytest-dev/pytest-django) from 4.5.2 to 4.8.0.
- [Release notes](https://github.com/pytest-dev/pytest-django/releases)
- [Changelog](https://github.com/pytest-dev/pytest-django/blob/master/docs/changelog.rst)
- [Commits](pytest-dev/pytest-django@v4.5.2...v4.8.0)

---
updated-dependencies:
- dependency-name: pytest-django
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -4,7 +4,7 @@ git+https://github.com/ministryofjustice/opg-response.git#egg=django-incident-re
 django-health-check==3.16.5
 django-decorator-include
 pytest-mock
-pytest-django==4.5.2
+pytest-django==4.8.0
 python-dotenv==0.20.0
 gunicorn==20.1.0
 psycopg2-binary==2.9.3