Fix remaining lint errors

app/models/comment.rb

@@ -8,7 +8,7 @@ class Comment < ApplicationRecord
   validates :content, length: { maximum: 512 }
 
   after_create do
-    Subscription.subscribe self.user, answer
+    Subscription.subscribe user, answer
     Subscription.notify self, answer
   end
 

app/models/subscription.rb

@@ -32,7 +32,7 @@ class Subscription < ApplicationRecord
         { target_id: source.id, target_type: Comment, recipient_id: s.user_id, new: true, type: Notification::Commented }
       end
 
-      Notification.insert_all!(notifications)
+      Notification.insert_all!(notifications) # rubocop:disable Rails/SkipsModelValidations
     end
 
     def denotify(source, target)