gh-105145: Deprecate Py_GetPath() function (#105179)

Deprecate old Python initialization functions:

* PySys_ResetWarnOptions()
* Py_GetExecPrefix()
* Py_GetPath()
* Py_GetPrefix()
* Py_GetProgramFullPath()
* Py_GetProgramName()
* Py_GetPythonHome()

_tkinter.c uses sys.executable instead of Py_GetProgramName()
and uses sys.prefix instead of Py_GetPrefix().