Possible type fix

Author: sgonorov

src/python/py_utils.hpp

@@ -19,7 +19,7 @@ namespace ov::genai::pybind::utils {
 // When StreamerVariant is used utf-8 decoding is done by pybind and can lead to exception on incomplete texts.
 // Therefore strings decoding should be handled with PyUnicode_DecodeUTF8(..., "replace") to not throw errors.
 using PyBindStreamerVariant = std::variant<
-    std::function<std::optional<uint16_t>(std::string)>,
+    std::function<std::optional<uint16_t>(py::str)>,
     std::shared_ptr<StreamerBase>,
     std::monostate>;