Ensure only actual releases get published on PyPI · OpenSimulationInterface/open-simulation-interface@ec5e811

The following actions uses Node.js version which is deprecated and will be forced to run on node20: peaceiris/actions-gh-pages@v3. For more info: https://github.blog/changelog/2024-03-07-github-actions-all-actions-will-run-on-node20-instead-of-node16-by-default/