bpo-32388: Remove cross-version binary compatibility requirement in tp_flags (GH-4944)

It is now allowed to add new fields at the end of the PyTypeObject struct without having to allocate a dedicated compatibility flag in tp_flags.

This will reduce the risk of running out of bits in the 32-bit tp_flags value.
diff --git a/Modules/xxlimited.c b/Modules/xxlimited.c
index 190f993..ffc04e0 100644
--- a/Modules/xxlimited.c
+++ b/Modules/xxlimited.c
@@ -123,7 +123,7 @@
     "xxlimited.Xxo",
     sizeof(XxoObject),
     0,
-    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_HAVE_FINALIZE,
+    Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
     Xxo_Type_slots
 };