[3.13] gh-117657: Fix missing atomic in dict_resize (GH-119312) (#119417

)

gh-117657: Fix missing atomic in dict_resize (GH-119312)

Fix missing atomic in dict_resize
(cherry picked from commit 2b3fb76)

Co-authored-by: Dino Viehland <dinoviehland@meta.com>

Objects/dictobject.c

@@ -2003,7 +2003,7 @@ dictresize(PyInterpreterState *interp, PyDictObject *mp,
         if (oldvalues->embedded) {
             assert(oldvalues->embedded == 1);
             assert(oldvalues->valid == 1);
-            oldvalues->valid = 0;
+            FT_ATOMIC_STORE_UINT8(oldvalues->valid, 0);
         }
         else {
             free_values(oldvalues, IS_DICT_SHARED(mp));