jpackage adds the "signed" property to the app image file (".jpackage.xml") when bundling an app image with signing.

This property is redundant because it duplicates the signing information baked into the bundle by the "/usr/bin/codesign" tool during signing.

It doesn't have a value as a hint for jpackage that it should sign a native bundle in two-step packaging because a signing key option (--mac-signing-key-user-name or --mac-installer-sign-identity) must still be explicit on the command line to make signing work.

Overall, there is no point in maintaining this property.