pybind11-protobuf: fix build with protobuf 34

Patch pybind11-protobuf to use absl::string_view in proto_cast_util.cc,
matching the updated Protobuf/DescriptorDatabase API.

pkgs/by-name/or/or-tools/pybind11-protobuf.nix

@@ -29,8 +29,15 @@ buildPythonPackage {
   ];
 
   postPatch = ''
+    # Original fix for version pinning
     substituteInPlace cmake/dependencies/CMakeLists.txt \
       --replace-fail 'find_package(protobuf 5.29.2 REQUIRED)' 'find_package(protobuf REQUIRED)'
+
+    # Fix for Protobuf 34.0 (absl::string_view migration)
+    substituteInPlace pybind11_protobuf/proto_cast_util.cc \
+      --replace-fail "const std::string& filename" "absl::string_view filename" \
+      --replace-fail "const std::string& symbol_name" "absl::string_view symbol_name" \
+      --replace-fail "const std::string& containing_type" "absl::string_view containing_type"
   '';
 
   nativeBuildInputs = [ cmake ];