Add infra endpoint to issue machine tokens for metal-hammer. - #194

A new Trusted Publisher for the currently running publishing workflow can be created by accessing the following link(s) while logged-in as an owner of the package(s):

Trusted Publishers allows publishing packages to PyPI from automated environments like GitHub Actions without needing to use username/password combinations or API tokens to authenticate with PyPI. Read more: https://docs.pypi.org/trusted-publishers

The workflow was run with the 'attestations: true' input, but an explicit password was also set, disabling Trusted Publishing. As a result, the attestations input is ignored.