bpo-38304: Remove PyConfig.struct_size (GH-16500) (GH-16508)

For now, we'll rely on the fact that the config structures aren't covered by the stable ABI.

We may revisit this in the future if we further explore the idea of offering a stable embedding API.

(cherry picked from commit bdace21b769998396d0ccc8da99a8ca9b507bfdf)

PC/python_uwp.cpp

@@ -165,12 +165,8 @@ int
 wmain(int argc, wchar_t **argv)
 {
     PyStatus status;
-
     PyPreConfig preconfig;
-    preconfig.struct_size = sizeof(PyPreConfig);
-
     PyConfig config;
-    config.struct_size = sizeof(PyConfig);
 
     const wchar_t *moduleName = NULL;
     const wchar_t *p = wcsrchr(argv[0], L'\\');
@@ -189,10 +185,7 @@ wmain(int argc, wchar_t **argv)
         }
     }
 
-    status = PyPreConfig_InitPythonConfig(&preconfig);
-    if (PyStatus_Exception(status)) {
-        goto fail_without_config;
-    }
+    PyPreConfig_InitPythonConfig(&preconfig);
     if (!moduleName) {
         status = Py_PreInitializeFromArgs(&preconfig, argc, argv);
         if (PyStatus_Exception(status)) {