Bump django-model-utils from 4.3.1 to 5.0.0

Bumps [django-model-utils](https://github.com/jazzband/django-model-utils) from 4.3.1 to 5.0.0.
- [Release notes](https://github.com/jazzband/django-model-utils/releases)
- [Changelog](https://github.com/jazzband/django-model-utils/blob/master/CHANGES.rst)
- [Commits](jazzband/django-model-utils@4.3.1...5.0.0)

---
updated-dependencies:
- dependency-name: django-model-utils
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements/production.txt

@@ -5,7 +5,7 @@ django-anymail[postmark]==10.0
 django-autoslug==1.9.9
 django-constance[redis]==2.9.1
 django-crispy-forms==1.14.0
-django-model-utils==4.3.1
+django-model-utils==5.0.0
 django-multiselectfield==0.1.12
 django-taggit==1.2.0
 django-timezone-field==5.1