Cleanup dockerfiles

scripts/Dockerfile-ubuntu_21_04

@@ -4,7 +4,7 @@ ARG DEBIAN_FRONTEND=noninteractive
 ARG TZ="Europe/London"
 
 RUN apt-get update -y && \
-    apt-get install -y \
+    apt-get install -y --no-install-recommends \
                         build-essential \
                         cmake \
                         git \
@@ -28,9 +28,8 @@ RUN apt-get update -y && \
                         libxtst-dev \
                         nvidia-cuda-dev \
                         nvidia-cuda-toolkit \
-    && \
-    apt-get clean && \
-    apt-get autoclean
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
 
 COPY build-private.sh /root/build.sh