fix: add patch cache buster to Dockerfile

Dockerfile

@@ -20,6 +20,9 @@ RUN cd /root/DeepGEMM && python3 setup.py build_ext --inplace
 
 # Copy our DeepSeek V4 patch over vLLM's model file
 COPY patches/deepseek_v4.py /usr/local/lib/python3.12/dist-packages/vllm/model_executor/models/deepseek_v4.py
+# Bust cache for patch changes
+ARG PATCH_CACHE_BUSTER=0
+RUN echo "Patch cache buster: $PATCH_CACHE_BUSTER" > /dev/null
 
 # Verify everything imports
 RUN python3 -c "import deep_gemm; print('DeepGEMM NVFP4 OK')" && \