Bump django-debug-toolbar from 4.1.0 to 4.2.0 in /requirements

Bumps [django-debug-toolbar](https://github.com/jazzband/django-debug-toolbar) from 4.1.0 to 4.2.0.
- [Release notes](https://github.com/jazzband/django-debug-toolbar/releases)
- [Changelog](https://github.com/jazzband/django-debug-toolbar/blob/main/docs/changes.rst)
- [Commits](jazzband/django-debug-toolbar@4.1...4.2)

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

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