Remove somewhat unnecessary change

Author: huydhn

.github/ci_configs/vllm/Dockerfile.tmp_vllm

@@ -334,7 +334,7 @@ RUN --mount=type=cache,target=/root/.cache/uv \
     uv pip install --system /wheels/xformers/*.whl --verbose
 
 # Build flashinfer from source.
-ARG torch_cuda_arch_list="8.0;8.9;9.0a;10.0a;12.0"
+ARG torch_cuda_arch_list='8.0;8.9;9.0a;10.0a;12.0'
 # install package for build flashinfer
 # see issue: https://github.com/flashinfer-ai/flashinfer/issues/738
 
@@ -353,7 +353,6 @@ RUN --mount=type=cache,target=/root/.cache/ccache \
     git clone --depth 1 --recursive --shallow-submodules \
         --branch ${FLASHINFER_GIT_REF} \
         ${FLASHINFER_GIT_REPO} flashinfer \
-    && export UV_TORCH_BACKEND=cu$(echo $CUDA_VERSION | cut -d. -f1,2 | tr -d '.') \
     && echo "Building FlashInfer with AOT for arches FLASHINFER_CUDA_ARCH_LIST: ${FLASHINFER_CUDA_ARCH_LIST}, TORCH_CUDA_ARCH_LIST ${TORCH_CUDA_ARCH_LIST}" \
     && cd flashinfer \
     && python3 -m flashinfer.aot \