Fix warning about casing mismatch between "FROM" and "as"

Dockerfile

@@ -2,30 +2,30 @@
 
 # Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
 ARG RUBY_VERSION=3.2.0
-FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim as base
+FROM registry.docker.com/library/ruby:$RUBY_VERSION-slim AS base
 
 # Rails app lives here
 WORKDIR /rails
 
 # Set production environment
 ENV RAILS_ENV="production" \
-    BUNDLE_DEPLOYMENT="1" \
-    BUNDLE_PATH="/usr/local/bundle" \
-    BUNDLE_WITHOUT="development"
+  BUNDLE_DEPLOYMENT="1" \
+  BUNDLE_PATH="/usr/local/bundle" \
+  BUNDLE_WITHOUT="development"
 
 
 # Throw-away build stage to reduce size of final image
-FROM base as build
+FROM base AS build
 
 # Install packages needed to build gems
 RUN apt-get update -qq && \
-    apt-get install --no-install-recommends -y build-essential git libvips pkg-config
+  apt-get install --no-install-recommends -y build-essential git libvips pkg-config
 
 # Install application gems
 COPY Gemfile Gemfile.lock ./
 RUN bundle install && \
-    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
-    bundle exec bootsnap precompile --gemfile
+  rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
+  bundle exec bootsnap precompile --gemfile
 
 # Copy application code
 COPY . .
@@ -42,8 +42,8 @@ FROM base
 
 # Install packages needed for deployment
 RUN apt-get update -qq && \
-    apt-get install --no-install-recommends -y curl libsqlite3-0 libvips && \
-    rm -rf /var/lib/apt/lists /var/cache/apt/archives
+  apt-get install --no-install-recommends -y curl libsqlite3-0 libvips && \
+  rm -rf /var/lib/apt/lists /var/cache/apt/archives
 
 # Copy built artifacts: gems, application
 COPY --from=build /usr/local/bundle /usr/local/bundle
@@ -51,7 +51,7 @@ COPY --from=build /rails /rails
 
 # Run and own only the runtime files as a non-root user for security
 RUN useradd rails --create-home --shell /bin/bash && \
-    chown -R rails:rails db log storage tmp
+  chown -R rails:rails db log storage tmp
 USER rails:rails
 
 # Entrypoint prepares the database.