[OpenVINO] Fixed Docker.openvino build (vllm-project#11732)

Signed-off-by: Ilya Lavrenov <[email protected]>

Author: ilya-lavrenov

Dockerfile.openvino

@@ -14,6 +14,7 @@ ARG GIT_REPO_CHECK=0
 RUN --mount=type=bind,source=.git,target=.git \
     if [ "$GIT_REPO_CHECK" != 0 ]; then bash tools/check_repo.sh ; fi
 
+RUN python3 -m pip install -U pip
 # install build requirements
 RUN PIP_EXTRA_INDEX_URL="https://download.pytorch.org/whl/cpu" python3 -m pip install -r /workspace/requirements-build.txt
 # build vLLM with OpenVINO backend