Make sure jobs are enqueued only after all transactions are committed

This should fix the recurring ActiveStorage::FileNotFoundError errors
from ActiveStorage::AnalyzeJob.

The issue is that, when images are not direct uploaded (e.g. a card
background image or avatar image), the AnalyzeJob has been getting
enqueued before the file itself was uploaded to blob storage.

Setting ActiveJob::Base.enqueue_after_transaction_commit = true makes
sure that jobs are always enqueued only once *all* transactions have
been committed.

This will be the Rails default at some point, but for now we still
need to explicitly set it.

Big thanks to @jeremy for the assist. 👏

lib/rails_ext/active_storage_analyze_job_retries.rb

@@ -1,23 +0,0 @@
-# Avoid sporadic ActiveStorage::FileNotFoundError errors
-#
-# Our direct-uploads aren't really direct. They first get buffered by CloudFlare
-# and then get sent to our storage servers. This can lead to situations where
-# a form was submitted, and ActiveStorage::Attachment created, and an
-# AnalyzeJob enqueued, but the file associated with the Blob doesn't yet exist
-# in our storage service.
-#
-# A simple olution ot this problem is just to retry the job a few times with
-# some backoff.
-#
-# Discussion: https://app.fizzy.do/5986089/cards/3056
-module ActiveStorageAnalyzeJobRetires
-  extend ActiveSupport::Concern
-
-  included do
-    retry_on ActiveStorage::FileNotFoundError, attempts: 15, wait: 2.seconds
-  end
-end
-
-ActiveSupport.on_load :active_storage_blob do
-  ActiveStorage::AnalyzeJob.prepend ActiveStorageAnalyzeJobRetires
-end