chore(deps): bump mozilla-django-oidc from 3.0.0 to 4.0.1 in /backend

Bumps [mozilla-django-oidc](https://github.com/mozilla/mozilla-django-oidc) from 3.0.0 to 4.0.1.
- [Release notes](https://github.com/mozilla/mozilla-django-oidc/releases)
- [Changelog](https://github.com/mozilla/mozilla-django-oidc/blob/main/HISTORY.rst)
- [Commits](mozilla/mozilla-django-oidc@3.0.0...4.0.1)

---
updated-dependencies:
- dependency-name: mozilla-django-oidc
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

backend/requirements.txt

@@ -23,7 +23,7 @@ django-prometheus==2.3.1
 django-filter==23.2
 pydantic==2.4.0
 redis==5.0.0
-mozilla-django-oidc==3.0.0
+mozilla-django-oidc==4.0.1
 # Dependencies used in local dev mode
 argh==0.26.2
 watchdog==2.1.9