fix: Add missing Cache-Control headers in the production config (#2518)

config/environments/production.rb

@@ -21,6 +21,9 @@ Rails.application.configure do
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
   config.public_file_server.enabled = ActiveModel::Type::Boolean.new.cast(ENV.fetch('RAILS_SERVE_STATIC_FILES', true))
+  config.public_file_server.headers = {
+    'Cache-Control' => "public, max-age=#{1.year.to_i}"
+  }
   # Compress JavaScripts and CSS.
   # config.assets.js_compressor = :uglifier
   # config.assets.css_compressor = :sass