[feature] age-plugin-yubikey support

[gmemstr]

It would be nice to be able to use my yubikey's age key to encrypt backups with https://github.com/str4d/age-plugin-yubikey.

[github-actions]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[gmemstr]

Not stale pls