posts: clean up delete! method.

* Remove unused `ban` and `without_mod_action` options.

* Don't try to set the `is_banned` flag during deletion.

* Don't create modactions for automatic "unapproved in 3 days"
  deletions, only to delete them after the fact.

app/logical/post_pruner.rb

@@ -2,36 +2,19 @@ class PostPruner
   def prune!
     prune_pending!
     prune_flagged!
-    prune_mod_actions!
   end
 
-  protected
-
   def prune_pending!
-    CurrentUser.scoped(User.system, "127.0.0.1") do
-      Post.where("is_deleted = ? and is_pending = ? and created_at < ?", false, true, 3.days.ago).each do |post|
-        post.delete!("Unapproved in three days")
-      rescue PostFlag::Error
-        # swallow
-      end
+    Post.pending.expired.each do |post|
+      post.delete!("Unapproved in three days", user: User.system)
     end
   end
 
   def prune_flagged!
-    CurrentUser.scoped(User.system, "127.0.0.1") do
-      Post.where("is_deleted = ? and is_flagged = ?", false, true).each do |post|
-        if post.flags.unresolved.old.any?
-          begin
-            post.delete!("Unapproved in three days after returning to moderation queue")
-          rescue PostFlag::Error
-            # swallow
-          end
-        end
+    Post.flagged.each do |post|
+      if post.flags.unresolved.old.any?
+        post.delete!("Unapproved in three days after returning to moderation queue", user: User.system)
       end
     end
   end
-
-  def prune_mod_actions!
-    ModAction.where(["creator_id = ? and description like ?", User.system.id, "deleted post %"]).destroy_all
-  end
 end