Bump django-stubs from 1.14.0 to 1.15.0 (#814)

Bumps [django-stubs](https://github.com/typeddjango/django-stubs) from 1.14.0 to 1.15.0.
- [Release notes](https://github.com/typeddjango/django-stubs/releases)
- [Commits](typeddjango/django-stubs@1.14.0...1.15.0)

---
updated-dependencies:
- dependency-name: django-stubs
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements-dev.txt

@@ -12,6 +12,6 @@ responses==0.22.0
 
 # mypy and PEP 561 stubs
 mypy==1.0.1
-django-stubs==1.14.0
+django-stubs==1.15.0
 djangorestframework-stubs==1.8.0
 types-requests==2.28.11.8