Update comment about building MRO dict

Co-authored-by: Victor Stinner <[email protected]>

Author: sergey-miryanov

Objects/typeobject.c

@@ -11351,7 +11351,7 @@ fixup_slot_dispatchers(PyTypeObject *type)
 
     PyObject *mro = Py_NewRef(lookup_tp_mro(type));
 
-    // Try to prebuild MRO dict. We build it in bottom-top manner,
+    // Build MRO dict. We build it in bottom-top manner,
     // from bottom base to the top one, because the bottommost base
     // has more items then other and copying it is preferable than
     // merging.