Bump cython from 3.0.2 to 3.0.3 in /python/helpers (dependabot#8153)

Bumps [cython](https://github.com/cython/cython) from 3.0.2 to 3.0.3.
- [Release notes](https://github.com/cython/cython/releases)
- [Changelog](https://github.com/cython/cython/blob/master/CHANGES.rst)
- [Commits](cython/cython@3.0.2...3.0.3)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

python/helpers/requirements.txt

@@ -7,4 +7,4 @@ pipfile==0.0.2
 poetry==1.6.1
 
 # Some dependencies will only install if Cython is present
-Cython==3.0.2
+Cython==3.0.3