maintenance: fix db timeouts in regenerate_post_counts!

Disable database timeouts durings daily maintenance. Fixes
`regenerate_post_counts!` timing out. Remove calls to without_timeout
because otherwise it will reenable the timeout when trying to restore
the old timeout (see 97cc873a3f).

app/logical/danbooru_maintenance.rb

@@ -8,6 +8,7 @@ module DanbooruMaintenance
   end
 
   def daily
+    ActiveRecord::Base.connection.execute("set statement_timeout = 0")
     PostPruner.new.prune!
     Upload.prune!
     Delayed::Job.where('created_at < ?', 45.days.ago).delete_all
@@ -22,9 +23,7 @@ module DanbooruMaintenance
     TagChangeRequestPruner.reject_all
     Ban.prune!
 
-    ApplicationRecord.without_timeout do
-      ActiveRecord::Base.connection.execute("vacuum analyze") unless Rails.env.test?
-    end
+    ActiveRecord::Base.connection.execute("vacuum analyze") unless Rails.env.test?
   rescue Exception => exception
     rescue_exception(exception)
   end

app/logical/post_pruner.rb

@@ -1,10 +1,8 @@
 class PostPruner
   def prune!
-    Post.without_timeout do
-      prune_pending!
-      prune_flagged!
-      prune_mod_actions!
-    end
+    prune_pending!
+    prune_flagged!
+    prune_mod_actions!
   end
 
 protected