Apply Layout/LineLength rubocop rule

Note we're excluding a few files:

* Configuration files that weren't generated by us
* Migration files that weren't generated by us
* The Gemfile, since it includes an important comment that must be on
  the same line as the gem declaration
* The Budget::Stats class, since the heading statistics are a mess and
  having shorter lines would require a lot of refactoring

app/controllers/direct_uploads_controller.rb

@@ -8,7 +8,9 @@ class DirectUploadsController < ApplicationController
   helper_method :render_destroy_upload_link
 
   def create
-    @direct_upload = DirectUpload.new(direct_upload_params.merge(user: current_user, attachment: params[:attachment]))
+    @direct_upload = DirectUpload.new(
+      direct_upload_params.merge(user: current_user, attachment: params[:attachment])
+    )
 
     if @direct_upload.valid?
       @direct_upload.save_attachment