Add `account_id DESC` to optimize PrecomputeFeedService (#2967)

app/services/precompute_feed_service.rb

@@ -6,7 +6,8 @@ class PrecomputeFeedService < BaseService
   # @param [Account] account
   def call(_, account)
     redis.pipelined do
-      Status.as_home_timeline(account).limit(FeedManager::MAX_ITEMS / 4).each do |status|
+      # NOTE: Added `id desc, account_id desc` to `ORDER BY` section to optimize query.
+      Status.as_home_timeline(account).order(account_id: :desc).limit(FeedManager::MAX_ITEMS / 4).each do |status|
         next if status.direct_visibility? || FeedManager.instance.filter?(:home, status, account.id)
         redis.zadd(FeedManager.instance.key(:home, account.id), status.id, status.reblog? ? status.reblog_of_id : status.id)
       end