Fix `Rails/WhereExists` cop in app/validators (#28854)

.rubocop_todo.yml

@@ -88,8 +88,6 @@ Rails/WhereExists:
     - 'app/serializers/rest/announcement_serializer.rb'
     - 'app/services/activitypub/fetch_remote_status_service.rb'
     - 'app/services/vote_service.rb'
-    - 'app/validators/reaction_validator.rb'
-    - 'app/validators/vote_validator.rb'
     - 'app/workers/move_worker.rb'
     - 'lib/tasks/tests.rake'
     - 'spec/models/account_spec.rb'

app/validators/reaction_validator.rb

@@ -19,7 +19,7 @@ class ReactionValidator < ActiveModel::Validator
   end
 
   def new_reaction?(reaction)
-    !reaction.announcement.announcement_reactions.where(name: reaction.name).exists?
+    !reaction.announcement.announcement_reactions.exists?(name: reaction.name)
   end
 
   def limit_reached?(reaction)

app/validators/vote_validator.rb

@@ -35,7 +35,7 @@ class VoteValidator < ActiveModel::Validator
     if vote.persisted?
       account_votes_on_same_poll(vote).where(choice: vote.choice).where.not(poll_votes: { id: vote }).exists?
     else
-      account_votes_on_same_poll(vote).where(choice: vote.choice).exists?
+      account_votes_on_same_poll(vote).exists?(choice: vote.choice)
     end
   end