move main ENV section in Dockerfiles

dockerfiles/bookworm.Dockerfile

@@ -3,6 +3,12 @@ ARG BASE_REGISTRY="docker.io"
 ARG DEBIAN_VERSION="bookworm"
 FROM ${BASE_REGISTRY}/ruby:${RUBY_VERSION}-slim-${DEBIAN_VERSION} AS base
 
+ENV RACK_ENV="production" \
+  BUNDLE_DEPLOYMENT=true \
+  BUNDLE_PATH="/usr/local/bundle" \
+  BUNDLE_WITHOUT="development test" \
+  RUBY_YJIT_ENABLE=true
+
 WORKDIR /kubernaut
 
 RUN rm -f /etc/apt/apt.conf.d/docker-clean
@@ -19,11 +25,6 @@ RUN <<EOT
   gem install -N bundler
 EOT
 
-ENV RACK_ENV="production" \
-  BUNDLE_DEPLOYMENT=true \
-  BUNDLE_PATH="/usr/local/bundle" \
-  BUNDLE_WITHOUT="development test" \
-  RUBY_YJIT_ENABLE=true
 
 ENV DEBIAN_FRONTEND="noninteractive"