[deps] Update django-phonenumber-field requirement

Updates the requirements on [django-phonenumber-field](https://github.com/stefanfoulis/django-phonenumber-field) to permit the latest version.
- [Release notes](https://github.com/stefanfoulis/django-phonenumber-field/releases)
- [Changelog](https://github.com/stefanfoulis/django-phonenumber-field/blob/main/CHANGELOG.rst)
- [Commits](django-phonenumber-field/django-phonenumber-field@8.1.0...8.4.0)

---
updated-dependencies:
- dependency-name: django-phonenumber-field
  dependency-version: 8.4.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,7 +1,7 @@
 django-organizations>=2.5.0,<2.6.0
 django-extensions>=3.2,<4.2
 django-allauth[socialaccount]>=65.12.0,<65.14.0
-django-phonenumber-field>=8.1.0,<8.2.0
+django-phonenumber-field>=8.1.0,<8.5.0
 phonenumbers>=9.0.10,<9.1.0
 openwisp-utils[rest,celery] @ https://github.com/openwisp/openwisp-utils/archive/refs/heads/1.3.tar.gz
 packaging