build: Reduce intermediate layers (#7408)

Author: krishung5

build.py

@@ -1082,25 +1082,20 @@ def create_dockerfile_linux(
 """
     if "tensorrtllm" in backends:
         df += """
-
-RUN ldconfig
-# Remove contents that are not needed in runtime
-RUN ARCH="$(uname -i)" \\
-      && rm -fr ${TRT_ROOT}/bin ${TRT_ROOT}/targets/${ARCH}-linux-gnu/bin ${TRT_ROOT}/data \\
-      && rm -fr  ${TRT_ROOT}/doc ${TRT_ROOT}/onnx_graphsurgeon ${TRT_ROOT}/python \\
-      && rm -fr ${TRT_ROOT}/samples  ${TRT_ROOT}/targets/${ARCH}-linux-gnu/samples
-
 # Install required packages for TRT-LLM models
-RUN python3 -m pip install --upgrade pip \\
-      && pip3 install transformers
-
-# ldconfig for TRT-LLM
-RUN find /usr -name libtensorrt_llm.so -exec dirname {} \; > /etc/ld.so.conf.d/tensorrt-llm.conf
-RUN find /opt/tritonserver -name libtritonserver.so -exec dirname {} \; > /etc/ld.so.conf.d/triton-tensorrtllm-worker.conf
-
+# Remove contents that are not needed in runtime
 # Setuptools has breaking changes in version 70.0.0, so fix it to 69.5.1
 # The generated code in grpc_service_pb2_grpc.py depends on grpcio>=1.64.0, so fix it to 1.64.0
-RUN pip3 install setuptools==69.5.1 grpcio-tools==1.64.0
+RUN ldconfig && \
+    ARCH="$(uname -i)" && \
+    rm -fr ${TRT_ROOT}/bin ${TRT_ROOT}/targets/${ARCH}-linux-gnu/bin ${TRT_ROOT}/data && \
+    rm -fr ${TRT_ROOT}/doc ${TRT_ROOT}/onnx_graphsurgeon ${TRT_ROOT}/python && \
+    rm -fr ${TRT_ROOT}/samples ${TRT_ROOT}/targets/${ARCH}-linux-gnu/samples && \
+    python3 -m pip install --upgrade pip && \
+    pip3 install --no-cache-dir transformers && \
+    find /usr -name libtensorrt_llm.so -exec dirname {} \; > /etc/ld.so.conf.d/tensorrt-llm.conf && \
+    find /opt/tritonserver -name libtritonserver.so -exec dirname {} \; > /etc/ld.so.conf.d/triton-tensorrtllm-worker.conf && \
+    pip3 install --no-cache-dir setuptools==69.5.1 grpcio-tools==1.64.0
 
 ENV LD_LIBRARY_PATH=/usr/local/tensorrt/lib/:/opt/tritonserver/backends/tensorrtllm:$LD_LIBRARY_PATH
 """