[deps] Update phonenumbers requirement from ~=9.0.13 to ~=9.0.15

Updates the requirements on [phonenumbers](https://github.com/daviddrysdale/python-phonenumbers) to permit the latest version.
- [Commits](daviddrysdale/python-phonenumbers@v9.0.13...v9.0.15)

---
updated-dependencies:
- dependency-name: phonenumbers
  dependency-version: 9.0.15
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -2,7 +2,7 @@ django-organizations~=2.5.0
 django-extensions>=3.2,<4.2
 django-allauth[socialaccount]~=65.8.1
 django-phonenumber-field~=8.1.0
-phonenumbers~=9.0.13
+phonenumbers~=9.0.15
 openwisp-utils[rest,celery] @ https://github.com/openwisp/openwisp-utils/tarball/1.2
 packaging
 django-sesame~=3.2.3