Bust relationship cache key (#37760)

app/models/concerns/relationship_cacheable.rb

@@ -10,7 +10,7 @@ module RelationshipCacheable
   private
 
   def remove_relationship_cache
-    Rails.cache.delete(['relationship', account_id, target_account_id])
-    Rails.cache.delete(['relationship', target_account_id, account_id])
+    Rails.cache.delete(['relationships', account_id, target_account_id])
+    Rails.cache.delete(['relationships', target_account_id, account_id])
   end
 end