gh-81057: Move OS-Related Globals to _PyRuntimeState (gh-100082)

https://github.com/python/cpython/issues/81057

Include/internal/pycore_runtime_init.h

@@ -26,6 +26,7 @@ extern "C" {
         }, \
         .obmalloc = _obmalloc_state_INIT(runtime.obmalloc), \
         .pyhash_state = pyhash_state_INIT, \
+        .os = _OS_RUNTIME_INIT, \
         .interpreters = { \
             /* This prevents interpreters from getting created \
               until _PyInterpreterState_Enable() is called. */ \