Removing the PIP cache from the built image (#4766)

Dockerfile

@@ -49,6 +49,10 @@ RUN apt-get update && \
 
 WORKDIR /app
 
+# Disalbe PIP Cache and Version Check
+ENV PIP_DISABLE_PIP_VERSION_CHECK=1
+ENV PIP_NO_CACHE_DIR=1
+
 # We first copy only the requirements file, to avoid rebuilding on every file
 # change.
 COPY requirements.txt requirements_bundles.txt requirements_dev.txt requirements_all_ds.txt ./