Bump django-csp from 3.7 to 3.8

Bumps [django-csp](https://github.com/mozilla/django-csp) from 3.7 to 3.8.
- [Release notes](https://github.com/mozilla/django-csp/releases)
- [Changelog](https://github.com/mozilla/django-csp/blob/main/CHANGES)
- [Commits](mozilla/django-csp@3.7...3.8)

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

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