[llvm] Revert "[GISEL] Add IRTranslation for shufflevector on scalable vector types" (PR #84330)

[David Blaikie via llvm-commits]

dwblaikie wrote:

Per: https://llvm.org/docs/CodeReview.html#code-review-workflow if you're just creating PRs for precommit checking/revert convenience, please apply the `skip-precommit-approval` label to clarify they aren't intended for precommit review.

https://github.com/llvm/llvm-project/pull/84330