fix: add skip-existing flag to production PyPI workflow

Add skip-existing: true to the production PyPI workflow to match TestPyPI behavior and handle existing versions gracefully.

Author: FirstUnicorn

.github/workflows/publish-pypi.yml

@@ -68,3 +68,5 @@ jobs:
 
       - name: Publish to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          skip-existing: true