DEV: Remove logical OR assignment of constants (#29201)

Constants should always be only assigned once. The logical OR assignment
of a constant is a relic of the past before we used zeitwerk for
autoloading and had bugs where a file could be loaded twice resulting in
constant redefinition warnings.

app/models/user_summary.rb

@@ -79,7 +79,7 @@ class UserSummary
     user_counts(liked_users)
   end
 
-  REPLY_ACTIONS ||= [UserAction::RESPONSE, UserAction::QUOTE, UserAction::MENTION]
+  REPLY_ACTIONS = [UserAction::RESPONSE, UserAction::QUOTE, UserAction::MENTION]
 
   def most_replied_to_users
     replied_users = {}