Currently, when an owner attempts to create a "Pending Publisher" for a project that already exists and that they already own, they get the same error as when they don't own the project:

Ideally, we would just create a regular publisher for them instead, or at the very least provide a more meaningful error message in this case.

Original issue below:

What's the problem this feature will solve?
It currently isn't possible to have a separate Trusted Publisher workflow for development and official workflows because more than one workflow is not permitted from the same project repository.

Describe the solution you'd like
I have a Github Actions workflow publish_package_dev which publishes alpha and beta releases to test.pypi.org, and another workflow publish_package which publishes non development tagged releases to pypi.org.

However, when setting up a Trusted Publisher workflow for the test repository then it is no longer possible to add a Trusted Publisher for the non-test version of PyPi because it complains that "This project name is already in use".