[CI] Add PD Disaggregation aarch64 test (#16572)

Signed-off-by: Shangming Cai <csmthu@gmail.com>

docker/Dockerfile

@@ -273,6 +273,7 @@ RUN --mount=type=cache,target=/root/.cache/pip \
 RUN --mount=type=cache,target=/root/.cache/pip \
     python3 -m pip install \
     datamodel_code_generator \
+    mooncake-transfer-engine==0.3.8.post1 \
     pre-commit \
     pytest \
     black \
@@ -286,14 +287,6 @@ RUN --mount=type=cache,target=/root/.cache/pip \
     cubloaty \
     google-cloud-storage
 
-# Install mooncake
-RUN --mount=type=cache,target=/root/.cache/pip \
-    if [ "$GRACE_BLACKWELL" = "1" ]; then \
-        python3 -m pip install mooncake-transfer-engine==0.3.7.post2; \
-    else \
-        python3 -m pip install mooncake-transfer-engine==0.3.8.post1; \
-    fi
-
 # Build and install sgl-model-gateway (install Rust, build, then remove to save space)
 RUN --mount=type=cache,target=/root/.cache/pip \
     curl --proto '=https' --tlsv1.2 --retry 3 --retry-delay 2 -sSf https://sh.rustup.rs | sh -s -- -y \