Support App Store Connect API Keys with Xcode >= 13

[Chris Araman]

From the Xcode 13 Release Notes:

xcodebuild now supports the use of App Store Connect API keys for authentication with the Apple Developer website. This enables the use of automatic signing via xcodebuild in headless environments, such as build machines and continuous integration setups. To use API keys with xcodebuild, create an API key on App Store Connect and pass the key along with its identifier and your team’s issuer identifier to xcodebuild using the new parameters authenticationKeyPath, authenticationKeyID, and authenticationKeyIssuerID, respectively. When creating a key, you can assign it a role to control its permissions for performing automatic signing tasks. To learn more about creating and managing keys, see Creating API Keys for App Store Connect API. (51444716)

This looks like it might allow for a better way to enable automatic code signing when invoking Xcode 13 and later.