Fix indexing scheduler trying to index when Elasticsearch is disabled (#19805)

Fix #19646

app/workers/scheduler/indexing_scheduler.rb

@@ -7,6 +7,8 @@ class Scheduler::IndexingScheduler
   sidekiq_options retry: 0
 
   def perform
+    return unless Chewy.enabled?
+
     indexes.each do |type|
       with_redis do |redis|
         ids = redis.smembers("chewy:queue:#{type.name}")