posts: remove rating, note, and status locks.

Remove the ability for users to lock ratings, note, and post statuses.

Historically the majority of locked posts were from 10+ years ago when
certain users habitually locked ratings and notes on every post they
touched for no reason. Nowadays most posts have been unlocked. Only a
handful of locked posts are left, none of which deserve to be locked.

The is_rating_locked, is_note_locked, and is_status_locked columns still
exist in the database, but aren't used.

app/policies/post_policy.rb

@@ -55,18 +55,6 @@ class PostPolicy < ApplicationPolicy
     record.visible?(user)
   end
 
-  def can_lock_rating?
-    user.is_builder?
-  end
-
-  def can_lock_notes?
-    user.is_builder?
-  end
-
-  def can_lock_status?
-    user.is_admin?
-  end
-
   def can_use_mode_menu?
     user.is_gold?
   end
@@ -84,9 +72,6 @@ class PostPolicy < ApplicationPolicy
     [
       :tag_string, :old_tag_string, :parent_id, :old_parent_id,
       :source, :old_source, :rating, :old_rating, :has_embedded_notes,
-      (:is_rating_locked if can_lock_rating?),
-      (:is_note_locked if can_lock_notes?),
-      (:is_status_locked if can_lock_status?),
     ].compact
   end