forgejo-runner: mark broken on darwin

The tests currently fail to execute on darwin, which may indicate a
sandboxing issue. Likely needs someone to care for forgejo ci/cd on
darwin.

pkgs/by-name/fo/forgejo-runner/package.nix

@@ -92,6 +92,8 @@ buildGoModule rec {
   };
 
   meta = with lib; {
+    # Cannot process container options: '--pid=host --device=/dev/sda': 'unknown server OS: darwin'
+    broken = stdenv.hostPlatform.isDarwin;
     description = "Runner for Forgejo based on act";
     homepage = "https://code.forgejo.org/forgejo/runner";
     changelog = "https://code.forgejo.org/forgejo/runner/releases/tag/${src.rev}";