pedro martelletto

sk-api: separate flags used for FIDO signature verification from sk-api flags

2

Use separate flags to reduce the risk of future confusion/conflict between WebAuthn/FIDO and sk-api flags (which are similar in concept, but serve a fundamentally different purpose).

remove duplicate checks introduced with SSH_BUG_RSASIGMD5's removal in https://github.com/openssh/openssh-portable/commit/2a7e3449.

Interactions with FIDO authenticators may block due to user interaction (touch). Most FIDO2 authenticators (e.g. Yubikeys) observe a 30-second timeout, but that's not guaranteed by the FIDO2 spec. On U2F-only...

- actions: move cygwin to windows-2025; - actions: build libfido2 on windows-2025 as well.