Skip Py_Finalize to avoid threading module assertion errors

In embedded Python scenarios, Py_Finalize triggers threading._shutdown()
which can fail with assertion errors when executor threads have used
PyGILState_Ensure/Release. The threading module tracks these threads
internally and expects specific state during shutdown.

Since the process will clean up resources on exit anyway, we skip
Py_Finalize. This is a common pattern for embedded Python applications.

Author: benoitc

c_src/py_nif.c

@@ -627,7 +627,15 @@ static ERL_NIF_TERM nif_finalize(ErlNifEnv *env, int argc, const ERL_NIF_TERM ar
         g_main_thread_state = NULL;
     }
 
+    /* For embedded Python, Py_Finalize() can cause issues with threading module
+     * shutdown when executor threads have used PyGILState_Ensure/Release.
+     * The process will clean up resources on exit, so we skip finalization.
+     *
+     * Note: If explicit cleanup is needed in the future, consider using
+     * Py_FinalizeEx() or manually clearing atexit handlers before finalize. */
+#if 0
     Py_Finalize();
+#endif
     g_python_initialized = false;
 
     return ATOM_OK;