math_opt: python cleanup

Author: Mizux

ortools/math_opt/core/python/BUILD.bazel

@@ -52,6 +52,7 @@ pybind_extension(
             "//ortools/math_opt/core:solver_debug",
             "//ortools/util:solve_interrupter",
             "//ortools/util/python:py_solve_interrupter_lib",
+            "@abseil-cpp//absl/base:nullability",
             "@abseil-cpp//absl/memory",
             "@abseil-cpp//absl/status:statusor",
             "@pybind11_abseil//pybind11_abseil:import_status_module",

ortools/math_opt/core/python/solver.cc

@@ -17,12 +17,14 @@
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
 
+#include <cstdint>
 #include <functional>
 #include <memory>
 #include <string>
 #include <utility>
 #include <vector>
 
+#include "absl/base/nullability.h"
 #include "absl/memory/memory.h"
 #include "absl/status/statusor.h"
 #include "ortools/base/status_macros.h"