Bump phonenumbers from 9.0.28 to 9.0.29 in /backend

Bumps [phonenumbers](https://github.com/daviddrysdale/python-phonenumbers) from 9.0.28 to 9.0.29.
- [Commits](daviddrysdale/python-phonenumbers@v9.0.28...v9.0.29)

---
updated-dependencies:
- dependency-name: phonenumbers
  dependency-version: 9.0.29
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

backend/pyproject.toml

@@ -24,7 +24,7 @@ dependencies = [
   "gevent~=25.9.0",
   "gunicorn~=25.3.0",
   "ngohub~=0.1.0",
-  "phonenumbers~=9.0.0",
+  "phonenumbers~=9.0.29",
   "psutil~=7.2.0",
   "psycopg2-binary~=2.9.0",
   "pycognito~=2024.5.0",