Remove the option to compile cython during the docker build. It hasn't been used in a while and is broken in upstream again (#553)

Author: gshtras

docker/Dockerfile.rocm

@@ -1,6 +1,5 @@
 # default base image
 ARG REMOTE_VLLM="0"
-ARG USE_CYTHON="0"
 ARG BUILD_RPD="1"
 ARG COMMON_WORKDIR=/app
 ARG BASE_IMAGE=rocm/vllm-dev:base
@@ -36,12 +35,10 @@ FROM fetch_vllm_${REMOTE_VLLM} AS fetch_vllm
 # -----------------------
 # vLLM build stages
 FROM fetch_vllm AS build_vllm
-ARG USE_CYTHON
 # Build vLLM
 RUN cd vllm \
     && python3 -m pip install -r requirements/rocm.txt \
     && python3 setup.py clean --all  \
-    && if [ ${USE_CYTHON} -eq "1" ]; then python3 tests/build_cython.py build_ext --inplace; fi \
     && python3 setup.py bdist_wheel --dist-dir=dist
 FROM scratch AS export_vllm
 ARG COMMON_WORKDIR