Use ad-hoc signing when archiving on CI
Use ad-hoc signing when archiving on CI

See the "SIGNING IDENTITIES" section in the manual entry for
`codesign(1)` for details. This allows us to sign without a signing
identity on CI.

Uberchord/Tweaks,flovilmart/Tweaks,Uberchord/Tweaks,flovilmart/Tweaks