Fix being able to appeal a strike unlimited times (#18529)

Peculiarity of the `has_one` association is that the convenience
creation method deletes the previous association even if the new
one is invalid

app/services/appeal_service.rb

@@ -14,7 +14,8 @@ class AppealService < BaseService
   private
 
   def create_appeal!
-    @appeal = @strike.create_appeal!(
+    @appeal = Appeal.create!(
+      strike: @strike,
       text: @text,
       account: @strike.target_account
     )