Update cache installation

Author: mc-nv

tools/gen_ort_dockerfile.py

@@ -141,7 +141,8 @@ def dockerfile_for_linux(output_file):
 ENV CMAKE_CUDA_COMPILER_LAUNCHER="ccache"
 ENV VERBOSE=1
 RUN apt-get update \\
-      && apt-get install -y --no-install-recommends ccache && ccache -p
+      && apt-get install -y --no-install-recommends ccache && ccache -p \\
+      && rm -rf /var/lib/apt/lists/*
 """.format( os.getenv("CCACHE_REMOTE_STORAGE") )
 
         df += """