python3Packages.libarcus: fix build against protobuf 3.18+

Still needs upstream resolution,
but we can grab a Vcpkg patch in the meantime

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

···
 { lib, buildPythonPackage, python, fetchFromGitHub
+, fetchpatch
 , cmake, sip_4, protobuf, pythonOlder }:
 
 buildPythonPackage rec {
···
     sha256 = "1ahka8s8fjwymyr7pca7i7h51ikfr35zy4nkzfcjn946x7p0dprf";
   };
 
-  disabled = pythonOlder "3.4.0";
+  patches = [
+    # Fix build against protobuf 3.18+
+    # https://github.com/Ultimaker/libArcus/issues/121
+    (fetchpatch {
+      url = "https://raw.githubusercontent.com/coryan/vcpkg/f69b85aa403b04e7d442c90db3418d484e44024f/ports/arcus/0001-fix-protobuf-deprecated.patch";
+      sha256 = "0bqj7pxzpwsamknd6gadj419x6mwx8wnlfzg4zqn6cax3cmasjb2";
+    })
+  ];
+
+  disabled = pythonOlder "3.4";
 
   propagatedBuildInputs = [ sip_4 ];
   nativeBuildInputs = [ cmake ];