Issue #19437: Fix PyCData_GetContainer() of ctypes, handle PyDict_New() failure

Modules/_ctypes/_ctypes.c

@@ -2331,6 +2331,8 @@ PyCData_GetContainer(CDataObject *self)
     if (self->b_objects == NULL) {
         if (self->b_length) {
             self->b_objects = PyDict_New();
+            if (self->b_objects == NULL)
+                return NULL;
         } else {
             Py_INCREF(Py_None);
             self->b_objects = Py_None;