Fixes #122379 It looks like `iter_contains()` in dynamo expects to take in something like `iter_contains(List[VariableTracker], VariableTracker])`. Previously, when we called this function where the list in question was a `RangeVariable`, we would pass in `RangeVariable.items` as our list. This is wrong, though since `RangeVariable.items` just contains the underlying [start, stop, step]. It looks like `unpack_var_sequence` does the right thing of "materializing" the range into a list of `VariableTrackers`, so I used that instead. cc voznesenskym penguinwu EikanWang jgong5 Guobing-Chen XiaobingSuper zhuhaozhe blzheng wenzhe-nrv jiayisunx chenyang78 kadeng chauhang [ghstack-poisoned]