Modify release script to support yubikey sig (#8574)
Modify release script to support yubikey sig (#8574)

Using `tools/offline-sigrequest.sh` is annoying. A while ago I looked into how we could use our yubikeys for our Windows code signing signatures and in the process of doing that learned how to use them for the certbot-auto signature. The certbot-auto signature won't be needed once https://github.com/certbot/certbot/issues/8526 is resolved and we've implemented that plan which will hopefully be in 2-3 months, but despite that, doing this still felt worth it to me.

The script still defaults to using `tools/offline-sign.sh`, but you can set an environment variable to use the yubikey instead. I tested both branches here and it worked.
lmcro/letsencrypt,letsencrypt/letsencrypt,stweil/letsencrypt,letsencrypt/letsencrypt,stweil/letsencrypt,lmcro/letsencrypt