[MLIR][LLVM] Remove last typed pointer remnants from tests (#71232)

This commit removes all LLVM dialect typed pointers from the lit tests.
Typed pointers have been deprecated for a while now and it's planned to
soon remove them from the LLVM dialect.

Related PSA:
https://discourse.llvm.org/t/psa-removal-of-typed-pointers-from-the-llvm-dialect/74502