Implement ValidPGPKey type
For tracking valid (not verified!) OpenPGP key fingerprint strings of upstream developers, we need to implement a ValidPGPKey
type, which wraps a String
and validates for correct length (see repod for an example: https://gitlab.archlinux.org/archlinux/repod/-/blob/cc0e43c7c858c679027068639e7db554fb78aa21/repod/files/srcinfo.py#L331-340).