Update Dockerfile, arg instead of env

Dockerfile

@@ -9,15 +9,13 @@ ARG ArduinoDownloadUrl=https://github.com/arduino/arduino-cli/releases/download/
 ARG ArduinoPackage=arduino-cli_0.29.0_Linux_64bit.tar.gz
 ARG ArduinoUID="1000"
 ARG ArduinoGID="1000"
-ENV USER arduino
+ARG USER="arduino"
 
 RUN \
   apt update && \
-  apt install -y vim-tiny && \
-  apt install -y python-cheetah && \
-  apt install -y python3 && \
+  apt upgrade -y && \
+  apt install -y python3-cheetah && \
   pip install pyserial && \
-  rm -rf /var/lib/apt/lists/* && \
   cd /tmp && \
   wget ${ArduinoDownloadUrl}/${ArduinoPackage} && \
   tar -xzf ${ArduinoPackage} && \
@@ -44,7 +42,3 @@ RUN \
 
 CMD ["/bin/bash"]
 
-
-  
-  
-