[deps] Update pytest-django requirement from ~=4.8.0 to ~=4.9.0

Updates the requirements on [pytest-django](https://github.com/pytest-dev/pytest-django) to permit the latest version.
- [Release notes](https://github.com/pytest-dev/pytest-django/releases)
- [Changelog](https://github.com/pytest-dev/pytest-django/blob/main/docs/changelog.rst)
- [Commits](pytest-dev/pytest-django@v4.8.0...v4.9.0)

---
updated-dependencies:
- dependency-name: pytest-django
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements-test.txt

@@ -1,4 +1,4 @@
-pytest-django~=4.8.0
+pytest-django~=4.9.0
 pytest-asyncio~=0.24.0
 pytest-cov~=5.0.0
 openwisp-utils[qa,selenium]~=1.1.0