⬆️ Bump pydantic-core from 2.16.3 to 2.18.4

Bumps [pydantic-core](https://github.com/pydantic/pydantic-core) from 2.16.3 to 2.18.4.
- [Release notes](https://github.com/pydantic/pydantic-core/releases)
- [Commits](pydantic/pydantic-core@v2.16.3...v2.18.4)

---
updated-dependencies:
- dependency-name: pydantic-core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements.txt

@@ -28,7 +28,7 @@ paddle-billing-client==0.2.6
     # via django-paddle-billing (pyproject.toml)
 pydantic==2.7.3
     # via api-client-pydantic
-pydantic-core==2.16.3
+pydantic-core==2.18.4
     # via pydantic
 requests==2.32.3
     # via api-client