Refactors pyspiel.cc to use py::overload_cast wherever possible (this is only possible due to C++17 support).
Refactors pyspiel.cc to use py::overload_cast wherever possible (this is only possible due to C++17 support).

PiperOrigin-RevId: 276322926
Change-Id: Ic3b0e36465f2f905949f96f889a7d9049b4a9a7f

deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel,deepmind/open_spiel