python311Packages.protobuf: mark as broken for protobuf >= 25

pkgs/development/python-modules/protobuf/default.nix

···
     homepage = "https://developers.google.com/protocol-buffers/";
     license = licenses.bsd3;
     maintainers = with maintainers; [ knedlsepp ];
+    # Tests are currently failing because backend is unavailable and causes tests to fail
+    # Progress tracked in https://github.com/NixOS/nixpkgs/pull/264902
+    broken = lib.versionAtLeast protobuf.version "25";
   };
 }