Bump django-stubs from 1.16.0 to 4.2.0

Bumps [django-stubs](https://github.com/typeddjango/django-stubs) from 1.16.0 to 4.2.0.
- [Release notes](https://github.com/typeddjango/django-stubs/releases)
- [Commits](typeddjango/django-stubs@1.16.0...4.2.0)

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

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

requirements/requirements-test.lock.txt

@@ -50,11 +50,11 @@ django==4.2
     # via
     #   django-stubs
     #   django-stubs-ext
-django-stubs==1.16.0
+django-stubs==4.2.0
     # via
     #   -r requirements/requirements-test.in
     #   djangorestframework-stubs
-django-stubs-ext==0.8.0
+django-stubs-ext==4.2.0
     # via django-stubs
 djangorestframework-stubs==1.10.0
     # via -r requirements/requirements-test.in
@@ -254,8 +254,6 @@ sqlparse==0.4.4
     # via django
 stevedore==5.0.0
     # via doc8
-tomli==2.0.1
-    # via django-stubs
 tomlkit==0.11.7
     # via pylint
 tornado==6.2