Revert "[dynamo][guards] Use lazy variable tracker for func defaults (#121388)"
This reverts commit 04a5d6e8d3f09ee6741484bcfea022228f747b09.
Reverted https://github.com/pytorch/pytorch/pull/121388 on behalf of https://github.com/osalpekar due to causing executorch model-test failures internally. See [D54707529](https://www.internalfb.com/diff/D54707529) ([comment](https://github.com/pytorch/pytorch/pull/121388#issuecomment-1992619251))
