Add Arm64 CPU Phase 1A CI bootstrap (#22123)

Co-authored-by: Ma Mingfei <mingfei.ma@intel.com>

docker/arm64.Dockerfile

@@ -0,0 +1,52 @@
+FROM ubuntu:24.04
+SHELL ["/bin/bash", "-c"]
+
+ARG SGLANG_REPO=https://github.com/sgl-project/sglang.git
+ARG VER_SGLANG=main
+
+RUN apt-get update && \
+    apt-get full-upgrade -y && \
+    DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends -y \
+    ca-certificates \
+    git \
+    curl \
+    wget \
+    vim \
+    gcc \
+    g++ \
+    make \
+    cmake \
+    libsqlite3-dev \
+    google-perftools \
+    libtbb-dev \
+    libnuma-dev \
+    numactl
+
+WORKDIR /opt
+
+RUN curl -LsSf https://astral.sh/uv/install.sh | sh && \
+    source $HOME/.local/bin/env && \
+    uv venv --python 3.12
+
+RUN echo -e '[[index]]\nname = "torch"\nurl = "https://download.pytorch.org/whl/cpu"\n\n[[index]]\nname = "torchvision"\nurl = "https://download.pytorch.org/whl/cpu"\n\n[[index]]\nname = "torchaudio"\nurl = "https://download.pytorch.org/whl/cpu"\n\n[[index]]\nname = "triton"\nurl = "https://download.pytorch.org/whl/cpu"' > .venv/uv.toml
+
+ENV UV_CONFIG_FILE=/opt/.venv/uv.toml
+ENV CMAKE_BUILD_PARALLEL_LEVEL=1
+
+WORKDIR /sgl-workspace
+RUN source $HOME/.local/bin/env && \
+    source /opt/.venv/bin/activate && \
+    git clone ${SGLANG_REPO} sglang && \
+    cd sglang && \
+    git checkout ${VER_SGLANG} && \
+    cd python && \
+    cp pyproject_cpu.toml pyproject.toml && \
+    uv pip install . && \
+    cd ../sgl-kernel && \
+    cp pyproject_cpu.toml pyproject.toml && \
+    uv pip install .
+
+ENV SGLANG_USE_CPU_ENGINE=1
+RUN echo 'source /opt/.venv/bin/activate' >> /root/.bashrc
+
+WORKDIR /sgl-workspace/sglang