Upgrade initializiation of PythonEngine to use PyConfig

[jmarrec]

Enhancement Request

I had a TODO for this for a while

OpenStudio/python/engine/PythonEngine.cpp

Lines 74 to 75 in cc1e0bb

	PythonEngine::PythonEngine(int argc, char* argv[]) : ScriptEngine(argc, argv), program(Py_DecodeLocale(pythonProgramName, nullptr)) {
	// TODO: modernize and use PyConfig (new in 3.8): https://docs.python.org/3/c-api/init_config.html

Py_SetPath was actually removed from 3.13 API

cf 998e13e

Detailed Description

https://docs.python.org/3/whatsnew/3.13.html

Possible Implementation

https://docs.python.org/3/c-api/init_config.html#c.PyConfig