Revert "Attempt to speed up production builds by skipping apt update (#144)"

This reverts commit 65b61dc241.

Dockerfile

@@ -15,14 +15,16 @@ FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base
 WORKDIR /rails
 
 # Install base packages
-RUN apt-get install --no-install-recommends -y \
+RUN apt-get update -qq && \
+    apt-get install --no-install-recommends -y \
     curl \
     libjemalloc2 \
     libvips \
     sqlite3 \
     libpq5 \
     vim \
-    wget
+    wget && \
+    rm -rf /var/lib/apt/lists /var/cache/apt/archives
 
 # Set production environment
 ENV RAILS_ENV="production" \
@@ -33,12 +35,10 @@ ENV RAILS_ENV="production" \
 # Throw-away build stage to reduce size of final image
 FROM base AS build
 
-# Install build dependencies
-RUN apt-get install --no-install-recommends -y \
-    build-essential \
-    git \
-    pkg-config \
-    libpq-dev
+# Install packages needed to build gems
+RUN apt-get update -qq && \
+    apt-get install --no-install-recommends -y build-essential git pkg-config libpq-dev && \
+    rm -rf /var/lib/apt/lists /var/cache/apt/archives
 
 # Install application gems
 COPY Gemfile Gemfile.lock ./