chore(deps): bump django-anymail from 12.0 to 13.0

Bumps [django-anymail](https://github.com/anymail/django-anymail) from 12.0 to 13.0.
- [Release notes](https://github.com/anymail/django-anymail/releases)
- [Changelog](https://github.com/anymail/django-anymail/blob/main/CHANGELOG.rst)
- [Commits](anymail/django-anymail@v12.0...v13.0)

---
updated-dependencies:
- dependency-name: django-anymail
  dependency-version: '13.0'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]