build(deps-dev): bump djangorestframework from 3.12.4 to 3.15.2

Bumps [djangorestframework](https://github.com/encode/django-rest-framework) from 3.12.4 to 3.15.2.
- [Release notes](https://github.com/encode/django-rest-framework/releases)
- [Commits](encode/django-rest-framework@3.12.4...3.15.2)

---
updated-dependencies:
- dependency-name: djangorestframework
  dependency-type: direct:development
...

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