Revert "[inductor] Add ir.Scan and lower aten.cumsum on CUDA (#106581)"
This reverts commit 5976a08eea1656a0f5420661b33e0937248f2097.
Reverted https://github.com/pytorch/pytorch/pull/106581 on behalf of https://github.com/peterbell10 due to This combined with #108803 uncovered a triton bug openai/triton#2298 ([comment](https://github.com/pytorch/pytorch/pull/106581#issuecomment-1719811113))
