Bump pytest-django from 3.8.0 to 4.1.0 in /requirements/testing
Bump pytest-django from 3.8.0 to 4.1.0 in /requirements/testing

Bumps [pytest-django](https://github.com/pytest-dev/pytest-django) from 3.8.0 to 4.1.0.
- [Release notes](https://github.com/pytest-dev/pytest-django/releases)
- [Changelog](https://github.com/pytest-dev/pytest-django/blob/master/docs/changelog.rst)
- [Commits](https://github.com/pytest-dev/pytest-django/compare/v3.8.0...v4.1.0)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
studentenportal/web,studentenportal/web,studentenportal/web,studentenportal/web,studentenportal/web