[llvm] [AMDGPU][True16][Codegen] remove another build_vector pattern from true16 (PR #149861)

[Brox Chen via llvm-commits]

broxigarchen wrote:

added a mir test which includes this pattern and pattern removed from https://github.com/llvm/llvm-project/pull/148715

https://github.com/llvm/llvm-project/pull/149861