sigstore is not a github action specific tool, you can use the python client with any CI/CD tool runner. You can attest with py_pi attestations and publish with

sigstore is not a github action specific tool, you can use the python client with any CI/CD tool runner. You can attest with py_pi attestations and publish with twine. When migrating the steps don't have to use the same syntax and tools, but for each step you can identify the desired outcome and create it without actions from the gh marketplace on a different CI/CD. More importantly, you consciously decided to make your pipeline not portable by using gh actions from the marketplace. This is not a requirement nor inevitable.