I've always felt uncomfortable adding other people's actions to my GitHub workflows, and this is exactly the kind of thing I was worried about.
I tend to stick to the official GitHub ones (actions/setup-python etc) plus the https://github.com/pypa/gh-action-pypi-publish one because I trust the maintainers to have good security habits.
That's exactly where I stand, and I feel partially vindicated by this outcome. There are so many useful Github actions made by randos, but I am not adding more unvetted dependencies to my project. I will unhappily copy and paste some useful code into my project rather than relying upon yet another mutable dependency.
I tend to stick to the official GitHub ones (actions/setup-python etc) plus the https://github.com/pypa/gh-action-pypi-publish one because I trust the maintainers to have good security habits.