`brew` has for some time packaged libfido2. We can use those builds to
simplify our pipeline. Ensure linking to the same OpenSSL version as
libfido2 through `brew deps`.

Next version introduces new features.

For setting PIN, enrolling fingerprints, and more.

For CTAP 2.0 authenticators' equivalent of FIDO_ERR_UV_BLOCKED.

Attempt using either built-in UV/PIN depending on the user selection of
authentication options.

This fixes #278 (more consistent PIN prompts).

CTAP2.0 with some form of UV configured will require UV for credential
creation.  Similarly, CTAP2.1 devices will require some form of UV if
the makeCredUvNotRqd option is not enabled.

While here, allow fallback to PIN if built-in UV is blocked.

Compare selection of user verification methods to what the authenticator
actually supports.

This fixes #278 (ensure that device actually has some form of UV).

While here, remove an unused anchor and refer to the authorization
mapping file consistently.

While here, move a notice about origin/appid to a more relevant section.

While here, use the proposed workaround for ownership problems [1].

[1] https://github.com/actions/checkout/issues/766