message: Mark header-implemented functions as inline
  This makes their signature to match functions from above.
  It also solves duplicate symbol errors in certain conditions.
diff: @@ -55,12 +55,12 @@ inline py::object PyoOrThrow(PyObject* ptr) {
  return Pyo(ptr);
  }
  -[[noreturn]] void ThrowTypeError(const char* error_message) {
  +[[noreturn]] inline void ThrowTypeError(const char* error_message) {
  PyErr_SetString(PyExc_TypeError, error_message);
  throw pybind11::error_already_set();
  }
  -[[noreturn]] void ThrowValueError(const char* error_message) {
  +[[noreturn]] inline void ThrowValueError(const char* error_message) {
  PyErr_SetString(PyExc_ValueError, error_message);
  throw pybind11::error_already_set();
  }
  