users: give all users unlimited favorites.

Let all users have unlimited favorites. Formerly the limit was 10k
favorites for regular members, 20k for Gold, and unlimited for Platinum.

Limiting favorites doesn't make sense since upvotes are unlimited.

app/models/user.rb

@@ -436,16 +436,6 @@ class User < ApplicationRecord
         end
       end
 
-      def favorite_limit(level)
-        if level >= User::Levels::PLATINUM
-          Float::INFINITY
-        elsif level == User::Levels::GOLD
-          20_000
-        else
-          10_000
-        end
-      end
-
       def favorite_group_limit(level)
         if level >= User::Levels::BUILDER
           Float::INFINITY
@@ -514,10 +504,6 @@ class User < ApplicationRecord
       User.tag_query_limit(level)
     end
 
-    def favorite_limit
-      User.favorite_limit(level)
-    end
-
     def favorite_group_limit
       User.favorite_group_limit(level)
     end