Build universal macOS binaries

Author: TheAssassin

.github/workflows/main.yml

@@ -33,8 +33,10 @@ jobs:
         run: bash -xe ci/build-nix.sh
 
   macos-release:
-    name: macOS (x86_64) release
+    name: macOS (universal) release
     runs-on: macos-14
+    environment:
+      CMAKE_OSX_ARCHITECTURES: "arm64;x86_64"
     steps:
       - uses: actions/checkout@v6
       - name: Checkout enet submodule