Maintainers need to keep a wall between the package publishing and public repos. Currently what people are doing is configuring the public repo as a Trusted Publisher directly. This means you can trigger the package publication from the repo itself, and the public repo is a huge surface area.

Configure the CI to make a release with the artefacts attached. Then have an entirely private repo that can't be triggered automatically as the publisher. The publisher repo fetches the artefacts and does the pypi/npm/whatever release.