Yes. I've done it. That's why there is an "approve and run" button when the PR comes from another repo. So that the maintainers can check if the PR is trying to exfiltrate secrets... or do other bad things of course.

The whole point of the github action secrets is that they are accessible by the CI when needed. Which means they are accessible. It's just a convenient way to store the secret in such a way that it is not completely public. But you still have to trust github and your maintainers.