A hand-crafted bundle based on OpenArena.app v0.8.8 from the official website.
It includes two hacky source-code fixes required to launch the game on a modern macOS version.
This is an x86-64 build, but it works on Apple Silicon Macs in the compatibility mode. Just launch the app bundle.
This bundle is not signed. To launch it on newer macOS systems, you have open the context menu and press "Open" while holding the control (^) key. Only then will the presented dialog have an option to trust and open the app. For details, see this Apple help page.