The DMG is only guaranteed to run on the same macOS version it was built on.
Homebrew package versions define the library versions bundled into the app.
MacPorts method (legacy, Intel-only)
A legacy Intel-only method using MacPorts exists in packaging/macosx/BUILD.txt. It includes custom patches for exiv2, gnutls, and gtk-osx-application, and uses gtk-mac-bundler to produce a DMG. Use this only if you specifically need a MacPorts-based build.