Move SHELL to the last stage

Signed-off-by: Simon Zhao <simonyansenzhao@gmail.com>

tools/docker/Dockerfile

@@ -61,14 +61,10 @@ ARG PYTHON_VERSION="3.11"
 ARG VIRTUAL_ENV="conda"
 
 ENV LANG=C.UTF-8 LC_ALL=C.UTF-8
-ENV DEBIAN_FRONTEND noninteractive
 
 WORKDIR /root
 USER root:root
 
-# -i option used to source bashrc (thus activating conda env) at every RUN statement
-SHELL ["/bin/bash", "-i", "-c"]
-
 # Exit if VIRTUAL_ENV is not specified correctly
 RUN if ! [[ "${VIRTUAL_ENV}" =~ ^(conda|venv|virtualenv)$ ]]; then \
         echo "VIRTUAL_ENV is now '${VIRTUAL_ENV}', which should be either 'conda', 'venv' or 'virtualenv'"; \
@@ -164,6 +160,9 @@ FROM deps AS final
 ARG RECO_LOCAL_DIR="./"
 ARG RECO_DIR="/tmp/recommenders"
 
+# -i option used to source bashrc (thus activating conda env) at every RUN statement
+SHELL ["/bin/bash", "-i", "-c"]
+
 COPY ${RECO_LOCAL_DIR} ${RECO_DIR}
 
 RUN RECO=$(if [ -z "${GIT_REF}" ]; then echo "${RECO_DIR}"; else echo "recommenders"; fi); \